* Please note that most treatment modalities listed below are based on conventional medicine. PreventDisease.com does not advocate the use of any pharmaceutical drug treatments. Long-term drug therapy is very detrimental to human health. All drug information is for your reference only and readers are strongly encouraged to research healthier alternatives to any drug therapies listed.
High
Blood Pressure
WHAT
IS HIGH BLOOD PRESSURE?
High blood pressure,
also called hypertension, is, simply, elevated pressure of the blood
in the arteries. Hypertension results from two major factors, which
can be present independently or together:
- The heart
pumps blood with excessive force.
- The body's
smaller blood vessels (known as the arterioles) narrow,
so that blood flow exerts more pressure against the vessels'
walls.
Although the
body can tolerate increased blood pressure for months and even years,
eventually the heart may enlarge (a condition called hypertrophy),
which is a major factor in heart failure . Such pressure
can also injure blood vessels in the heart, kidneys, the brain,
and the eyes.
Two numbers are used to describe blood pressure:
- Systolic.
The systolic pressure (the higher and first number) measures
the force that blood exerts on the artery walls as the heart
contracts to pump out the blood.
- Diastolic.
The diastolic pressure (the lower and second number) is the
measurement of force as the heart relaxes to allow the blood
to flow into the heart.
Blood pressure
is measured in millimeters of mercury (mm Hg). For example, excellent
blood pressure would be less than 120/80 mm Hg (systolic/diastolic).
Blood pressure is now categorized as optimal, normal, high normal,
and hypertensive. The hypertensive category is further divided,
according to severity. [ See Table Blood Pressure and Its
Treatments.]
American expert groups recommend that any blood pressure above normal
should be treated. Some experts are concerned, however, that such
guidelines may unnecessarily increase the use of antihypertensive
drugs.
Health dangers from blood pressure may vary among different age
groups and depending on whether systolic or diastolic pressure (or
both) is elevated. A third measurement, pulse pressure, is becoming
important as an indicator of severity:
- High systolic
blood pressure (the first and higher number) appears to be a
significant indicator for heart complications, including death,
in all ages, but especially in middle-aged and older adults.
In fact, elevated systolic pressure may pose a significant danger
for heart events and stroke events even when diastolic is normal,
a condition called isolated systolic hypertension .
The wider the spread between the systolic and diastolic measurements,
the greater the danger. Isolated systolic hypertension is the
most common form of hypertension in people older than fifty;
in one study it comprised 87% of hypertension cases in people
between ages 50 and 59.
- High diastolic
pressure (the second and lower number) is a strong predictor
of heart attack and stroke in young adults and in people
of any age with essential hypertension . This is high
blood pressure from unknown causes and occurs in the great majority
of cases. [See Hypertension Categories, below.]
- Pulse
pressure is the difference between the systolic and the diastolic
readings. It appears to be an indicator of stiffness and inflammation
in the blood-vessel walls. The greater the difference between
systolic and diastolic numbers, the stiffer and more injured
the vessels are thought to be. Although not yet used by physicians
to determine treatment, evidence is suggesting that it may prove
to be a strong predictor of heart problems, particularly in
older adults. Some studies suggest that in people over 45 years
old, every 10-mm Hg increase in pulse pressure increases the
risk for stroke increases by 11%, cardiovascular disease by
10%, and overall mortality by 16%. (In younger adults the risks
are even higher.)
Hypertension
Categories
Some experts
categorize hypertension into the following types:
Primary Hypertension. Primary hypertension is also known
as essential or idiopathic hypertension . About 90%
of all high blood pressure cases are this type. The causes of essential
hypertension are unknown but are certainly based on complex processes
in all major organs and systems, including the heart, blood vessels,
nerves, hormones, and the kidneys.
Secondary Hypertension. Secondary hypertension comprises
about 5% of high blood pressure cases. In this condition, the cause
has been identified.
Isolated Systolic Hypertension. This occurs when systolic
hypertension is over 160 mm Hg but diastolic pressure is normal.
It is related to arteriosclerosis (hardening of the arteries).
Pregnancy Induced Hypertension. This condition occurs during
pregnancy if blood pressure increases by more than 15 mm Hg above
normal.
White Coat Hypertension. This form of hypertension is elevated
blood pressure that occurs only during a visit to the doctor's office.
|
BLOOD PRESSURE RANGES AND ACTIONS TAKEN
|
Blood Pressure Category
|
Ranges for Most Adults (systolic/diastolic)
|
Actions Taken after Initial Diagnosis
|
Optimal Blood Pressure (systolic/diastolic)
|
Systolic below 120 mm Hg
Diastolic below 80 mm Hg
|
No action.
|
Normal Blood Pressure
|
Systolic 120 to 130 mm Hg
Diastolic 80 to 85 mm Hg
(The upper numbers should be minimum goal for everyone, particularly
people with diabetes.)
|
Rechecked every two years.
|
High Normal Blood Pressure
|
Systolic 130 to 139 mm Hg
Diastolic 85 to 89 mm Hg
|
Blood pressure monitored at home and patient should be evaluated
for organ damage.
|
Hypertension (High Blood Pressure)
|
Systolic above 140 mm Hg
Diastolic above 90 mm Hg
(In middle age and older people, systolic pressure above 140
mm Hg suggests higher health risks even when diastolic pressure
is normal or low. )
|
|
Mild Hypertension (Stage 1)
|
Systolic 140 to 159 mm Hg
Diastolic 90 to 99 mm Hg
|
Same as high normal. If no organ damage, retesting at least
twice a week for several weeks. If organ damage present, start
drug therapy.
|
Moderate Hypertension (Stage 2)
|
Systolic 160 to 179 mm Hg
Diastolic 100 to 109 mm Hg
|
Same as high normal. If no organ damage, retesting at least
twice a week for several weeks. If organ damage present, start
drug therapy.
|
Severe Hypertension (Stage 3)
|
Systolic 180 to 209 mm Hg
Diastolic 110 to 119 mm Hg
|
Same as high normal. Consider immediate drug therapy regardless
of organ damage evidence.
|
Very Severe Hypertension (Stage 4)
|
Systolic greater than 210 mm Hg
Diastolic greater than 120 mm Hg
|
Same as high normal. Consider immediate drug therapy regardless
of organ damage evidence.
|
Note: If one measurement is normal and the other elevated,
the higher category of either measurement is usually used
to determine severity. For example, if systolic pressure is
165 (moderate) and diastolic is 92 (mild), the patient would
still be diagnosed with moderate hypertension. It should be
strongly noted that a high systolic pressure compared to a
normal or low diastolic pressure should be a major focus of
concern in most adults.
|
|
Blood Pressure in Children
A child's
blood pressure is normally much lower than an adult's. Children
are at risk for hypertension if they exceed the following
levels:
-
Ages three to five: 116/76
-
Ages six to nine: 122/78
-
Ages 10 to 12: 126/82
-
Ages 13 to 15: 136/86
|
WHAT
WILL CONFIRM THE DIAGNOSIS OF HIGH BLOOD PRESSURE?
Measuring
Blood Pressure
It is a rare
physical examination that does not include blood pressure measurement.
The process is familiar to everyone:
- First,
patients should not smoke or drink caffeinated beverages within
30 minutes of the measurement.
- The standard
instrument used to measure blood pressure is called a mercury
sphygmomanometer. (Electronic devices are also available.)
- An inflatable
cuff with a meter attached is placed around the patient's arm
over the artery, while the patient is seated.
- The person
taking the blood pressure listens through a stethoscope.
- If a first
blood pressure reading is above normal, the health professional
may take two or more measurements separated by two minutes with
the patient sitting or lying down, as well as one measurement
taken after the patient has been standing for two minutes.
Although this
test has been used for more than 90 years, it is not completely
accurate or sensitive. The following can bias the results.
Falsely low pressure reading can be caused by the following:
- Recent
exercise.
- Not smoking
for a while after heavy, long-term smoking.
- White
coat normotension (also called isolated home hypertension).
This is a condition in which a person's blood pressure registers
as normal at the doctor's office, even though it is actually
somewhat elevated. It tends to occur in men, especially those
who are past smokers, older, or alcohol users. One study suggested
that it still posed a risk for heart problems that was similar
to uncontrolled hypertension.
Falsely high
pressure can result from the following:
- An arm
cuff that is too small.
- Talking
during the test.
- Having
recently consumed foods or beverages (such as coffee) that raise
blood pressure.
- White-coat
hypertension. This is a phenomenon in which a patient's blood
pressure rises in the presence of a physician and, presumably,
returns to normal at home. Some researchers suggest that the
incidence of true white coat hypertension is very low, only
5%, and that physicians should always suspect true hypertension
when blood pressure is elevated in the office. Studies have
further suggested that white-coat hypertension actually may
pose a risk for future heart problems, although the increased
danger appears to be small compared with the risk in those with
steady mild hypertension. If white-coat hypertension is suspected,
home monitoring is important.
If the outcome
is high normal or above, the patient should be monitored at home
and have further tests to determine if the organs are affected.
An average of all the measurements will be considered in the diagnosis
of hypertension. [ For details See Box Blood Pressure Ranges
and Actions taken.]
Home
Monitoring
Monitoring
Equipment. A number of home tests are available for checking
blood pressure between doctor visits: A physician may loan a patient
a portable unit that records blood pressure during a full day's
activity. This test, known as ambulatory monitoring, is particularly
useful for those who experience wide blood pressure swings, such
as those who have white-coat hypertension or show resistance to
drug therapy. In fact, according to one study, accurately measuring
blood pressure at home over a full day was a significantly better
predictor of cardiovascular risk than standard office-based measurements.
To improve clinical outcomes, devices are now available that allow
24-hour ambulatory blood pressure monitoring and electronically
store results for analysis by the physician. It is not clear if
their added benefits justify their expense, however.
Cuffs and Stethoscopes. Manual cuffs and stethoscopes are
fairly accurate, but they require practice to use, and the cuff
must be the right size (one size does not fit all). Devices that
use a digital readout and a cuff that can be electronically inflated
and deflated are proving to be as accurate as a stethoscope.
Blood Pressure Variations at Home. In general, everyone's
blood pressure varies in the same way throughout a given day. In
monitoring at home, it is important to note these changes:
- Blood
pressure is usually highest at work.
- It drops
slightly at home.
- It then
normally dips to its lowest level during sleep. There are important
exceptions. Certain people have a condition called nondipper
hypertension , in which blood pressure does not fall at
night. Postmenopausal women appear to be at particular risk
for this phenomenon, and it may pose a special danger for heart
disease and stroke (particularly in older African American women).
It has also been linked to salt-sensitivity and insulin resistance.
- Upon waking,
pressure in most people typically increases suddenly. In people
with severe high blood pressure, this is the highest risk period
for heart attack and stroke.
Some studies
have reported that when patients record and report their own blood
pressure, they are unreliable and don't always tell the truth. Despite
the difficulties and controversy surrounding this issue, home blood
pressure monitoring has been shown to encourage patients to use
measures that control their blood pressure and thereby reduce the
risk of cardiovascular events.
Physical
Examination for Complications of Hypertension
If blood pressure
is elevated, the physician will check the patient's pulse rate,
examine the neck for distended veins or an enlarged thyroid gland,
check the heart for enlargement and murmurs, and examine the abdomen
and the eyes.
Medical
History
If hypertension
is suspected, the physician should obtain the following information:
- A family
and personal medical history, especially incidence of high blood
pressure, stroke, heart problems, kidney disease, or diabetes.
- Risk factors
of heart disease and stroke, including tobacco use, salt intake,
obesity, physical inactivity, and unhealthy cholesterol levels.
- Any medications
being taken.
- Any symptom
that might indicate so-called secondary hypertension
(that is, caused by another disorder). Such symptoms include
headache, heart palpitations, excessive sweating, muscle cramps
or weakness, or excessive urination.
- Any emotional
or environmental factors that could affect blood pressure.
Laboratory
and Other Tests
If a physical
examination indicates hypertension, additional tests may help determine
whether it is secondary hypertension or essential hypertension
(no other disorder is present) and whether organ damage is
present. They include the following:
- Blood
tests and a urinalysis. (Performed to check for a number of
factors, including potassium levels, cholesterol, blood sugar,
infection, kidney function, and other possible problems. Measuring
blood levels of the protein creatinine, for example, is important
for all hypertensive patients in order to determine kidney damage.
Higher concentrations may also be an indicator of heart disease.)
- An electrocardiogram
(ECG).
- An exercise
stress test. This could be important for those with borderline
hypertension. Stress-induced blood pressure in such patients
has been associated with a risk for left ventricular hypertrophy,
a serious complication in which the muscles on the left side
of the heart become enlarged. Studies also suggest that an excessive
rise in systolic pressure during exercise indicates a risk for
coronary artery disease, and stroke.
WHAT
CAUSES HIGH BLOOD PRESSURE?
Essential
Hypertension
Hypertension
is referred to as essential, or primary, when the physician is unable
to identify a specific cause. It is by far the most common type
of high blood pressure. The causes of this type are unknown but
are likely to be a complex combination of genetic, environmental,
and other factors.
Genetic Factors. A number of genetic factors or interactions
between genes play a major role in essential hypertension. Experts
appear to have located the chromosomes (13 and 18) that house the
genes responsible for blood pressure regulation, although pinning
down the range of specific genes involved in hypertension is more
difficult.
Abnormalities in the Angiotensin-Renin-Aldosterone System.
Genes under intense study are those that regulate a group of hormones
known collectively as the angiotensin-renin-aldosterone system.
This system influences all aspects of blood pressure control, including
blood vessel contraction, sodium and water balance, and cell development
in the heart.
Experts believed that this system evolved millions of years ago
to protect early humans during drought or stress by retaining salt
and water and narrowing blood vessels to ensure adequate blood flow
and repair injured tissue. With industrialization, however, this
system wreaks havoc on modern humans by intensifying the effects
of our high-salt diets and sedentary lifestyle. Of particular importance
in these harmful responses are the hormone aldosterone and a peptide
(which are components of proteins) called angiotensin II.
Inherited Abnormalities in the Sympathetic Nervous System.
Studies suggest that some people with essential hypertension may
inherit abnormalities of the sympathetic nervous system .
This is the part of the autonomic nervous system that controls heart
rate, blood pressure, and the diameter of the blood vessels.
Insulin Resistance and Diabetes Type 2. Hypertension is
strongly associated with diabetes, both type 1 and 2. Kidney damage
is generally the cause of high blood pressure in diabetes type 1.
Obesity and insulin resistance are the factors associated with hypertension
in type 2 diabetes, the more common type. People with type 2 diabetes
generally have normal or high levels of insulin, a critical hormone
in the metabolism of sugar. However, they are unable to use the
insulin, the condition called insulin resistance . Without
insulin, blood glucose (sugar in the blood) rises, the hallmark
of diabetes.
Some research indicates that obesity is the one common element linking
insulin, diabetes type 2, and high blood pressure. Obesity is common
in both type 2 diabetes and hypertension. Oddly, however, studies
have found a stronger association between hypertension and insulin
resistance in thin patients as well as overweight people
with type 2 diabetes. Some research indicates that insulin resistance
may cause sodium retention, a contributor to high blood pressure.
In any case, regardless of the causal connections, people who have
both insulin resistance or full-blown diabetes plus hypertension
have a significantly greater chance for heart attack, kidney disease,
and stroke than people who have only high blood pressure.
Obesity. Obesity on its own has a number of possible effects
that could lead to hypertension. It may blunt certain actions of
insulin that open blood vessels, and it may cause structural changes
in the kidney and abnormal handling of sodium. It is also associated
with alterations in the systems that regulate blood flow.
Low Levels of Nitric Oxide. The gas nitric oxide can be
produced in the body, where it affects the smooth muscles cells
that line blood vessels; it helps keep them relaxed, flexible. It
may also help prevent blood clotting. Low levels of nitric oxide
have been observed in people with high blood pressure (particularly
in African Americans) and may be an important factor in essential
hypertension.
Secondary
Hypertension
Secondary hypertension
has recognizable causes, which are usually treatable or reversible.
Medical Conditions. A number of medical conditions can cause
secondary high blood pressure:
- Kidney
disease is the most common cause of secondary hypertension,
particularly in older people.
- Sleep
apnea, a disorder in which breathing halts briefly but repeatedly
during sleep, is now highly associated with hypertension. A
weak but still higher than normal association with high blood
pressure has even been observed in those who snore or have mild
sleep apnea. The relationship between sleep apnea and hypertension
has been thought to be largely due to obesity, but major studies
are finding a higher rate of hypertension in people with sleep
apnea regardless of their weight. Treating sleep apnea with
a device known as nasal continuous positive airway pressure
may have modest benefits blood pressure as well.
- Other
medical conditions that contribute to temporary hypertension
are pregnancy, cirrhosis, and Cushing's disease.
Medications.
Certain prescription and over-the-counter drugs can cause temporary
high blood pressure. Some include the following:
- Corticosteroids.
- Long-term
use of nonsteroidal anti-inflammatory drugs (NSAIDs) may injure
the kidney and is an important cause of secondary hypertension
in the elderly population. Such drugs include aspirin, ibuprofen
(Advil, Motrin, Rufen), naproxen (Anaprox, Naprosyn, Aleve),
and many others. Of these drugs, aspirin appears to have the
least detrimental effect on blood pressure.
- Cold medicines
containing pseudoephedrine have also been found to increase
blood pressure in hypertensive people, although they appear
to pose no danger for those with normal blood pressure.
- Oral contraceptives
(the Pill) increase the risk for high blood pressure, particularly
in women who are older, obese, smokers, or some combination.
Stopping the Pill nearly always reduces blood pressure, although
a recent study suggests that oral contraceptives may produce
a small but significant increase in diastolic pressure that
persists in some older women who have been off the Pill for
years.
Alcohol, Coffee,
and Cigarettes
- Alcohol.
An estimated 10% of hypertension cases are caused by alcohol
abuse (ie, three alcoholic drinks a day or more, with heavier
drinkers having higher pressure). In one study, binge-drinkers
had even higher blood pressure than people who drank regularly.
One study found alcohol abuse associated with low diastolic
but high systolic pressure. Moderate drinking (one or two drinks
a day) has benefits for the heart and may even protect against
some types of stroke. Of some concern was a study suggesting
the even low or moderate drinking may increase the risk for
hypertension in African Americans. Red wine specifically may
have chemicals that benefit blood pressure. (Red grape juice
may have the same advantages) It is critical, in any case,
for people who can't drink moderately to abstain from alcohol.
- Smoking.
Smoking is a major risk factor. One study reported that smokers
have blood pressures up to 10 points higher than nonsmokers.
- Caffeine.
Caffeine causes a temporary increase in blood pressure, which
has been thought to be harmless in people with normal blood
pressure. Studies are suggesting, however, that regular, heavy
coffee drinking (an average of 5 cups per day) can boost blood
pressure, and there is growing evidence that a high intake of
coffee may be harmful in people with hypertension and may even
increase their risk for stroke. Drinking coffee also increases
excretion of calcium, which also may affect blood pressure.
(Anyone who drinks coffee should maintain an adequate calcium
intake.)
Other Causes
of Secondary High Blood Pressure. Temporary high blood pressure
can result from a number of other conditions or substances.
- Stress.
- Intense
workouts (eg, snow shoveling, jogging, speed walking, tennis,
heavy lifting, heavy gardening).
- Long-term
consumption of large amounts of licorice.
- Exposure
to even low levels of lead also appears to cause hypertension
in adults. More studies are needed to clarify this relationship.
WHO
GETS HIGH BLOOD PRESSURE?
An estimated
50 million Americans have high blood pressure. Over 30% of these
people are unaware that their blood pressure is abnormal. And although
over half are on medication, only about quarter of them have their
blood pressure under good control. Older people are less likely
to be treated adequately. The majority of people with high blood
pressure have the mild type, but even this condition requires attention.
Age
and Gender
Age is the major
risk factor of hypertension. In both men and women, the risk for
high blood pressure increases as one ages. More men than women have
hypertension until age 55, After that the ratio reverses, and over
time women gain on men and finally overtake them. In all, mortality
rates from hypertension are higher in women than in men.
Ethnicity
Compared to Caucasians,
they have 1.8 times the rate of fatal stroke, 1.5 times the risk
for fatal heart disease, and 4.2 times the rates of end-stage kidney
disease. In general, about 36% of African men and women have hypertension;
it may account for over 40% of all deaths in this group.
In fact, the prevalence of high blood pressure among African Americans
is among the highest in the world. The rates of hypertension in
Hispanic Americans, Caucasians, and Native Americans are about equivalent
(ranging from 24% to 27%). (Individuals of Mexican descent, compared
to Spanish descent, may have a lower risk.) The rate is much lower
in Asian Pacific Islanders (9.7% in men and 8.4% in women). In one
study, however, nearly three quarters of older Japanese American
men were hypertensive.
A number of theories have addressed the reasons for this difference:
- Some studies
have indicated that African Americans may have lower levels
of nitric oxide and higher levels of a peptide called endothelin-1
(ET-1) than Caucasians. (Nitric oxide keeps blood vessels flexible
and open and ET-1 narrrows blood vessels.)
- African
Americans have a higher risk for an impaired response to angiotensin
(Ang II), which is a peptide important in regulating salt and
water balances. (African Americans are more likely to be salt-sensitive
than other groups.)
- and income
disparities and dietary issues may explain many of the differences
in blood pressure rates observed between ethnic groups. For
example, while African-Americans have a disproportionately high
rate of hypertension, one study in rural African villages, where
diets are rich in fish, reported only a 3% rate of high blood
pressure among the natives. Another study reported that Caucasian
as well as African Americans in the Southeast have a higher
incidence of hypertension and stroke than people in other US
regions. The Southeast also has a higher rate of obesity, stress,
anxiety, and depression, and diets low in potassium and high
in salt, all related to a lower socioeconomic level. In any
case, hypertension appears to be dangerously undertreated in
major minority groups Inadequately controlled hypertension is
the major factor for the higher mortality rate from heart disease
among African Americans.
Weight
Obesity. About one-third of patients with high blood pressure
are overweight. Even moderately obese adults have double the risk
of hypertension than people with normal weights. In fact, the increase
in blood pressure in aging Americans may be due primarily to weight
gain. (In other cultures old age does not necessarily coincide with
weight gain or high blood pressure.) Children and adolescents who
are obese are at greater risk for high blood pressure when they
reach adulthood.
Thinness. Interestingly, thin people with hypertension are
at higher risk for heart attacks and stroke than obese people with
high blood pressure. Experts surmise that thin people with hypertension
are likely to have conditions such as an enlarged heart or stiff
arteries that cause the high blood pressure and also pose greater
dangers to health.
Low Birth Weight. Low birth weight, particularly in females,
has been associated with high blood pressure in both childhood and
adulthood. (One study suggested that breast-feeding these babies
may help reduce this risk.) Another study reported high levels of
stress hormones in babies with low birth weight, which could increase
the risk for high blood pressure later on. Low-birth weight is also
associated with subsequent obesity, a major contributor to hypertension.
Family
History
Some experts
now believe that essential hypertension may be inherited in 30%
to 60% of cases. According to one study, being a brother or sister
of someone with premature coronary artery disease is a greater risk
factor for hypertension than having a parent with the disease. A
family history of heart disease is considered to be a major risk
factor for high blood pressure in younger adults (under 65).
Emotional
Factors
People who are
anxious or depressed may have over twice the risk for high blood
pressure than those without these problems.
Mental Stress. Recent evidence confirms the association between
stress and hypertension (high blood pressure). In one 20-year study,
for example, men who periodically measured highest on the stress
scale were twice as likely to have high blood pressure as those
with normal stress. The effects of stress on blood pressure in women
were less clear. Job stress and lack of career success have been
specifically linked to high blood pressure in both men and women.
Anxiety. Studies suggest that anxiety is risk factor for
hypertension, particularly in women.
Depression. There is increasing evidence that depression
has actual physiological effects that impair the heart, as well
as contributing to destructive behaviors, such as weight gain, smoking,
or alcohol abuse. In a 2000 study of young people, both African
Americans and Caucasians, those who scored highest on a depression
test had about twice the risk of high blood pressure as those with
the lowest score. This link was particularly strong in African Americans.
In fact, it was the strongest risk factor in this group.
Seasonal
Factors
Seasonal changes
may influence variations in blood pressure, with hypertension increasing
during cold months and declining during the summer, particularly
in smokers. While cold may narrow blood vessels, lack of light has
also been associated with higher blood pressure.
HOW
SERIOUS IS HIGH BLOOD PRESSURE?
Hypertension
can cause certain organs (called target organs), including the kidney,
eyes, and heart, to deteriorate over time. High blood pressure was
responsible for nearly 43,000 American deaths in 1999 and was listed
as the primary or contributing cause of death in an estimated 227,000
cases. The death rate from high blood pressure is estimated to have
increased by 21% between 1989 and 1999. High blood pressure contributes
to 75% of all strokes and heart attacks. It is particularly deadly
in African Americans.
Emergency
Conditions
Malignant hypertension,
an emergency condition resulting from untreated primary hypertension,
can be lethal. [ See What Are the Symptoms of High Blood
Pressure?, below.]
Stroke
About two-thirds
of people who suffer a first stroke have moderate elevated blood
pressure (160/95 mm Hg or above). Hypertensive people have up to
ten times the normal risk of stroke, depending on the severity of
the blood pressure. Hypertension is also an important cause of so-called
silent cerebral infarcts, which are blockages in the blood vessels
in the brain that may predict major stroke or progression to dementia
over time.
Mental
Problems and Dementia
Uncontrolled
chronic high blood pressure is also associated with reduced short-term
memory and mental abilities. Isolated systolic hypertension may
pose a particular risk for complications in the brain. Fortunately,
controlling blood pressure with medications can reduce or even prevent
memory loss and mental decline due to hypertension. (Antihypertensive
drugs may even help protect against Alzheimer's in people with genetic
susceptibility to this disease.)
Heart
Disease
Among older patients,
high blood pressure is the major risk factor for heart disease.
Two studies in 2001 further reported that high blood pressure in
young men poses a higher risk for heart disease later on, and in
one of the studies, fewer years of life.
Heart Attack. About half of people who suffer their first
heart attack have moderate (160/95 mm Hg) over above hypertension.
High blood pressure increases the risk for a heart attack by up
to five times, depending on the severity of the hypertension.
Heart Failure. Hypertension precedes congestive heart failure
in between 75% and 90% of heart failure cases. High blood pressure
has various effects that cause the heart to fail, including the
following:
- To compensate
for increased blood pressure, the heart must work harder to
pump blood, and so its muscles thicken (called hypertrophy),
usually in the left side (called left-ventricle dysfunction).
These thickened muscles pump inefficiently, and over time, the
force of their contractions weakens. The heart muscles then
have difficulty relaxing and filling the heart with blood. The
heart begins to fail.
- The failing
heart then triggers a number of hormonal and neurochemical mechanisms
to correct imbalances in blood pressure and flow. This response,
called remodeling, is helpful in the short run but very
destructive and irreversible over time.
- As part
of the remodeling process, the heart muscle cells elongate.
The muscular walls of the heart dilate and become thinner and
inefficient. The cells themselves undergo molecular changes
that result in calcium loss, a mineral crucial for healthy heart
contractions.
- The end-result
of remodeling is that the volume of blood pumped to the kidneys
falls, and the kidneys respond by retaining water and salt,
which, in turn, increases fluid build-up in the body.
- To make
matters worse, the body's arteries respond to a lower blood
volume by constricting; this forces the heart to work even harder
to pump blood through these narrowed vessels, thereby increasing
blood pressure, and the cycle continues.
Kidney
Disease
End-Stage
Kidney Disease. High blood pressure causes 30% of all cases
of end-stage kidney disease (medically referred to as end-stage
renal disease or ESRD). Only diabetes leads to more cases of kidney
failure. In fact, although antihypertensive therapy has reduced
the incidence of stroke and heart attack, the incidence in ESRD
has almost doubled in the last decade.
Kidney Cancer. Men with high blood pressure may also have
a higher risk of kidney cancer.
Effect
on the Eyes
High blood pressure
can injure the eyes, causing a condition called retinopathy.
Bone
Loss
Hypertension
also increases the elimination of calcium in urine that may lead
to loss of bone mineral density, a significant risk factor for fractures,
particularly in elderly women. In one study of Englishwomen, those
with the highest blood pressure lost bone density at nearly twice
the rate of those in the lowest range. It is not clear whether this
effect occurs in men or in non-Caucasian women.
Sexual
Dysfunction
Sexual dysfunction
is more common and more severe in men with hypertension, and particularly
in smokers, than it is in the general population. Many of the drugs
used to treat hypertension are thought to cause impotence as a side
effect; in these cases, it is reversible when the drugs are stopped.
More recent evidence is suggesting, however, that the disease process
that causes hypertension itself is the major cause of erectile dysfunction
in these men. Newer anti-hypertensive agents, including angiotensin-converting
enzyme (ACE) inhibitors and angiotensin-receptor blockers (ARBs),
are less associated with erectile dysfunction. In fact, ARBs, such
as losartan (Cozaar), may be particularly effective in restoring
erectile function in men with high blood pressure who suffer from
impotence. Sildenafil (Viagra) was reported to be successful in
achieving erections in almost two-thirds of patients with controlled
high blood pressure, but at this time its safety for men with uncontrolled
hypertension in unclear. [For more information see the
Report #15 Impotence (Erectile Dysfunction).]
Pregnancy
and Preeclampsia
Severe, sudden
high blood pressure in pregnant women is one component of a condition
called preeclampsia (commonly called toxemia) that can be very serious
for both mother and child. It occurs in up to 10% of all pregnancies,
usually in the third trimester of a first pregnancy, and resolves
immediately after delivery. Other symptoms and signs of preeclampsia
include protein in the urine, severe headaches, and swollen ankles.
This condition may be caused by a failure of the placenta to embed
properly in the uterus, which causes it to misconnect with the mother's
blood vessels. As a result, the fetus does not receive a sufficient
blood supply and the mother's own blood pressure increases to replace
it.
The reduced supply of blood to the placenta can cause low birth
weight and eye or brain damage in the fetus. Severe cases of preeclampsia
can cause kidney damage, convulsion, and coma in the mother and
can be lethal to both mother and child.
Women at risk for preeclampsia (particularly those with existing
hypertension) may benefit from having an ultrasound of uterine arteries
at 20 to 24 weeks' gestation followed, if abnormal, by 24-hour blood
pressure monitoring.
Outlook
for Children with Hypertension
Results of studies
evaluating outcomes of children with hypertension suggest that early
abnormalities, including enlarged heart and abnormalities in the
kidney and eyes, may occur even in children with mild hypertension.
Children and adolescents with hypertension should be monitored and
evaluated for any early organ damage.
WHAT
ARE THE SYMPTOMS OF HIGH BLOOD PRESSURE?
No
Symptoms
Hypertension
has aptly been called the "silent killer" because it usually produces
no symptoms. Untreated hypertension increases slowly over the years.
It is important, therefore, for anyone with risk factors to have
their blood pressure checked regularly and to make appropriate lifestyle
changes. Such recommendations are urged for individuals who have
overall high-normal blood pressure, mild or above systolic with
normal diastolic pressure, family histories of hypertension, or
who are overweight or over age 40.
Symptoms
of Malignant Hypertension
In rare cases
(fewer than one percent of hypertensive patients), the blood pressure
rises quickly (with diastolic pressure usually rising to 130 or
higher), resulting in malignant or accelerated hypertension. This
is a life-threatening condition and must be treated immediately.
People with uncontrolled hypertension or a history of heart failure
are at increased risk for this crisis.
People should call a physician immediately if these symptoms occur:
- Drowsiness.
- Confusion.
- Headache.
- Nausea.
- Loss of
vision.
WHAT
ARE THE GENERAL GUIDELINES FOR CHOOSING THE APPROPRIATE TREATMENTS
FOR HIGH BLOOD PRESSURE?
Determining
Treatments
Healthy life
style changes are imperative for anyone, and are critical for people
with even normal blood pressure and above. Drug treatments for hypertension
are proving to be very important, although it is not altogether
clear when they should be started, particularly for people with
high-normal or mild high blood pressure.
To help make basic treatment choices for people with high-normal
or high blood pressure, The National Heart, Lung, and Blood Institute
has created categories (denoted as Groups A, B, and C) according
to a patient's risk factors for heart disease. Applying these categories
to the severity of hypertension helps determine whether lifestyle
changes alone or medications are needed. [ See Table Treatment
Recommendations by Stage and Risk Groups.]
TREATMENT RECOMMENDATIONS BY STAGE AND RISK GROUPS
RISK GROUPS
|
BLOOD PRESSURE STAGES (systolic/diastolic)
|
|
High Normal Blood pressure
(130-139/85-89)
|
Mild (Stage 1) Blood Pressure
(140-159/90-99)
|
Moderate (Stage 2) Blood Pressure
(160-179/100-109)
|
Severe Blood Pressure (Stage 3 and 4)
(over 180/110)
|
Risk Group A
Have no risk factors for heart disease.* Note: only women
are in this group.
|
Life style changes only. (Exercise and dietary program with
regular monitoring.) It should be noted that high normal still
poses a risk for heart disease even in people with Group A.
|
Year trial of lifestyle changes only.
|
Lifestyle changes and medications.
|
Lifestyle changes and medications.
|
Risk Group B
Have at least one risk factor for heart disease* (excluding
diabetes) but have no target organ damage (such as in the
kidney, eyes, or heart or existing heart disease).
|
Lifestyle changes only.
|
Six month trial of lifestyle changes only.
(Medications considered for patients with multiple risk factors.)
|
Lifestyle changes and medications.
|
Lifestyle changes and medications.
|
Risk Group C
Have diabetes with or without target organ damage and existing
heart disease (with or without risk factors for heart disease).
|
Lifestyle changes and medications.
|
Lifestyle changes and medications.
|
Lifestyle changes and medications.
|
Lifestyle changes and medications.
|
* Risk factors for heart disease include the following: smoking,
unhealthy cholesterol and lipid levels, diabetes, being over
60 years old, being a man or postmenopausal woman, and women
under 65 and men under 55 with a family history of heart disease.
|
WHAT
LIFESTYLE CHANGES ARE NEEDED TO CONTROL HIGH BLOOD PRESSURE?
A 2001 study
suggested that following a simple dietary regimen may improve blood
pressure. It suggested that lowering the intake of protein, sodium,
and alcohol can improve both systolic and pulse pressures. Increasing
potassium intake improves both blood pressure measurements.
DASH
Diet.
A diet known
as Dietary Approaches to Stop Hypertension (DASH) is now recommended
as an important step in managing blood pressure. This diet is not
only rich in important nutrients and fiber but also includes foods
that contain far more electrolytes, potassium, calcium, and magnesium,
than are found in the average American diet. It makes the following
recommendations:
- Avoid
saturated fat (although include calcium-rich dairy products
that are no- or low-fat).
- When choosing
fats, select monounsaturated oils, such as olive or canola oils.
(One study reported a reduced need for anti-hypertension medication
in people with a high intake of virgin olive oil, but not sunflower
oil, a polyunsaturated fat.)
- Choose
whole grains over white flour or pasta products.
- Choose
fresh fruits and vegetables every day. Many of these foods are
rich in fiber, which may help lower blood pressure. Important
foods include most fruits (especially potassium-rich fruits
including bananas, oranges, prunes, and cantaloupes) and vegetables
(especially carrots, spinach, celery, alfalfa, mushrooms, lima
beans, potatoes, avocados, broccoli). Note: Grapefruit and bitter
oranges (also called Seville of sour oranges) boost the effects
of calcium-channel blocking drugs, which are often used for
hypertension. (Regular oranges do not appear to pose any hazard.)
- Include
nuts, seeds, or legumes (dried beans or peas) daily.
- Choose
modest amounts of protein (preferably fish, poultry, or soy
products). Soy in combination with fiber-rich foods or supplements
may have specific benefits. Oily fish may also be particularly
beneficial. They contain omega-3 fatty acids, which have been
associated with heart and nerve protection [ see below ].
In one study,
after eight weeks on the diet, subjects from a broad range of backgrounds
experienced a significant reduction in blood pressure. Evidence
now also suggests that it may be a good diet for lowering LDL cholesterol
levels--although the beneficial HDL levels also decline. The significance
of these effects are not yet known.
Salt
Restriction
A combination
of the DASH diet and salt restriction is extremely effective in
reducing blood pressure. (Each approach has positive benefits, but
the combination is best.) Some individuals should take particular
measures to restrict salt.
- People
at Risk for Salt-Sensitivity (African Americans, Diabetics,
the Elderly). About half of people with hypertension have
blood pressure that reacts significantly to salt. Such people
are known to be salt-sensitive. High-salt diets in anyone
who is salt-sensitive may harm the heart, kidney, and brain
and increase the risk for death, regardless of their blood pressure.
(Even people with normal blood pressure can be salt-sensitive
.) Among those at highest risk for salt sensitivity are
African Americans, people with diabetes, and elderly people.
A 2001 study, for example, reported that reducing sodium intake
in older people, including African Americans, was very effective
in controlling their hypertension. Still because testing for
salt-sensitivity is not easy, experts recommend that everyone
proactively restrict their daily salt-intake.
- Overweight
People. Overweight individuals may absorb and retain sodium
differently from people with normal weights. In fact, one 1999
study reported that high sodium intake was associated with an
increased risk of heart disease and all-cause mortality in overweight,
but not in normal weight, people. Unfortunately, because overweight
people generally consume more calories, they are also likely
take in more sodium.
- People
on Anti-Hypertensive Drugs. Restricting salt also enhances
the benefits of nearly all standard antihypertensive drugs by
reducing potassium loss, and may help protect against kidney
disease in patients who are also taking calcium-blocker drugs.
Everyone, regardless
of their blood pressure, should consume less than 2,400 milligrams
(about one teaspoon) of sodium each day. People with hypertension
should strive for even lower intake. Simply eliminating table and
cooking salt can be beneficial. Salt substitutes, such as Cardia,
containing mixtures of potassium, sodium, and magnesium are available,
but they are expensive. It should be noted, however, that about
75% of the salt in the typical American diet comes from processed
or commercial foods, not from food cooked at home, so the benefits
of table-salt substitutes are likely to be very modest. Some sodium
is essential to protect the heart, but most experts agree that the
amount is significantly less than that found in the average American
diet. If people cannot significantly reduce the amount of salt in
their diets, adding potassium-rich foods might help to restore a
healthy balance.
Potassium, Magnesium, and Calcium. Some experts believe
that sufficient intake of minerals, particularly potassium, magnesium,
and calcium, may be more beneficial than salt restriction for reducing
blood pressure.
- Potassium.
Studies have indicated that potassium deficiencies increase
the risk for high blood pressure. More important more recent
studies indicate that a potassium-rich diet may reduce hypertension.
The best source of potassium is from the fruits and vegetables
that contain them. In fact, there is some evidence that a potassium-rich
diet can reduce the risk of stroke by 22% to 40%. [For some
of these foods, see Dash Diet, above.] Some patients,
such as those taking certain diuretics that do not spare potassium,
may require supplements. Excess potassium, however, can cause
abdominal distress, muscle weakness, and, in rare cases, dangerous
heart events. Some people should be particularly cautious about
potassium supplements, including those with conditions, such
as diabetes or kidney disease, that increase potassium levels
or who are taking medications, such as ACE inhibitors or potassium-sparing
diuretics, that limit the kidney's ability to excrete potassium.
- Magnesium.
Some studies reported that magnesium supplements may induce
small but significant reductions in blood pressure. No major
studies, however, have been done on long-term benefits or risks
of magnesium supplements. A major 2001 study on diet found no
effect on blood pressure from magnesium intake from foods.
- Calcium.
Calcium regulates the tone of the smooth muscles lining blood
vessels, and population studies have found that people who have
sufficient dietary calcium have lower blood pressure than those
who do not. Hypertension itself increases calcium loss from
the body. Some, but not all, studies have found modest beneficial
effects on blood pressure from calcium supplements. Sufficient
calcium is important, in any case, for strong bones.
Supplements
Omega 3 Fatty
Acids. Omega 3 fatty acids (docosahexaenoic and eicosapentaenoic
acids) are found in oily fish. Studies are indicating that they
may have specific benefits for many medical conditions, including
hypertension. They appear to help keep blood vessels flexible and
may also help protect the nervous system. The fatty acids are also
available in supplements, although over-the-counter supplements
are not regulated and their effects on health are not known. The
long-term effects on blood pressure are not known.
Antioxidant Supplements. Antioxidants are any substances
that help the body eliminate oxidants, or oxygen free radicals,
which are damaging particles produced as part of the body's chemical
processes. Some antioxidant supplements, including vitamins C and
E and alpha-lipoic acid, are being studied for possible benefits
in protecting against hypertension by preventing injury in the blood
vessels. Alpha-lipoic acid for example prevented elevated blood
pressure in rats. Vitamin C apparently also has specific benefits
for hypertension by preventing dangerous effects on nitric acid,
the substance that keeps arteries flexible.
Caffeine
Intake, Alcohol, and Smoking
Everyone should
quit smoking and, if they drink alcohol, should do so in moderation.
In healthy people with normal blood pressure, drinking a couple
of cups of coffee a day is unlikely to do any harm. Caffeine drinkers,
however, might do better to choose tea, which may have beneficial
nutrients, and people with existing hypertension should avoid caffeine
altogether.
Weight
Loss
An estimated
97 million adults in the US are overweight or obese. Weight gain
seems to be a primary determinant in blood pressure increase, and
weight loss may be even more important than salt restriction in
controlling blood pressure. Losing weight, particularly in the abdominal
area, immediately reduces blood pressure and helps reduce heart
size. Weight loss, particularly accompanied by salt restriction,
may allow patients with mild hypertension, even older people, to
safely reduce or go off medications. The benefits of weight loss
on blood pressure appear to be durable. [For more information, see
the Report Weight Control and Diet .]
Exercise
Positive Effects
on Blood Pressure. Regular exercise helps keep arteries elastic,
even in older people, which in turn ensures blood flow and normal
blood pressure. Sedentary people have a 35% greater risk of developing
hypertension than athletes do.
High-intensity exercise may not lower blood pressure as effectively
as moderate intensity exercise. The following are some observations
that support this approach:
- In one
study, moderate exercise (jogging two miles a day) controlled
hypertension so well that more than half the patients who had
been taking drugs for high blood pressure were able to discontinue
their medication.
- Studies
have indicated that Yoga and Tai Chi, an ancient Chinese exercise
involving slow, relaxing movements, may lower blood pressure
almost as well as moderate-intensity aerobic exercises.
- Before
exercising, people with hypertension should avoid caffeinated
beverages, which increase heart rate, the workload of the heart,
and blood pressure during physical activity.
Negative Effects.
Each year an estimated 75,000 heart attacks (or 5% of all attacks)
occur after heavy exertion, leading to 25,000 deaths. Older people
and those with uncontrolled hypertension or other serious medical
conditions should be very cautious. Studies report that older people
who begin vigorous exercise are at a slightly higher than average
risk for a heart attack during the first year, but over time, regular
exercise is likely to be protective.
The following activities may pose particular dangers for high-risk
individuals.
- Intense
workouts (snow shoveling, slow jogging, speed walking, tennis,
heavy lifting, heavy gardening). They tend to stress the heart,
raise blood pressure for a brief period, and may cause spasms
in the arteries leading to the heart.
- Competitive
sports, which couple intense activity with aggressive emotions.
Effects of
Anti-Hypertensive Drugs on Exercise. Certain antihypertensive
medications, including diuretics and beta-blockers, can interfere
with exercise capacity. ACE inhibitors or calcium-channel blockers
are the best drugs for active individuals. However, patients who
must take drugs that interfere somewhat with exercise capability
should still adhere to an exercise program and consult a physician
on how best to balance medications with exercise.
Good
Sleep Habits
Insufficient
sleep may raise blood pressure in patients with hypertension, placing
them at increased risk of cardiovascular morbidity and mortality.
According to a 1999 Italian study, blood pressure and heart rate
were higher the morning after a sleep-deprived night compared with
the morning after a full night of sleep. Stress hormone levels increase
with sleeplessness, which can activate the sympathetic nervous system,
a strong player in hypertension. Patients who have chronic insomnia
or other severe sleep disturbances should consider consulting sleep
experts if life style measures are not helpful. Physicians whose
hypertensive patients are habitually poor sleepers should consider
long-acting blood pressure medications to help counteract the increase
in blood pressure that occurs in the early morning hours. [ See
the Report Insomnia.]
Stress
Reduction and Psychologic Therapy
Improving mood
or relieving stress may be helpful. The following are some studies
suggesting possible benefits:
- Studies
suggest that stress reduction programs, such as those that use
cognitive-behavioral therapy, can reduce blood pressure. In
some cases people can even go off medication.
- Two small
studies also reported that active religious faith was associated
with healthy blood pressure levels, possibly indicating the
combined benefits of a strong social network and reduced stress
from spiritual activities. (Listening to religious services
on the radio or watching them on television had no impact on
blood pressure.)
- Even pets
can provide healthful support. In a small 2001 study, medication
had no effect on blunting blood pressure that increased in response
to stress, but owning a pet did.
- In another
study, a simple relaxation technique called transcendental meditation
(TM), which involves silent repetition of a single sound, was
shown to be effective in reducing blood pressure.
WHAT
ARE THE GENERAL GUIDELINES FOR DRUG THERAPY FOR HIGH BLOOD PRESSURE?
Advantages
of Drug Treatments
Aggressive drug
treatment of long-term high blood pressure can significantly reduce
the incidence of mental decline and death from heart disease and
other serious physical effects of hypertension. In people with diabetes,
controlling both blood pressure and blood glucose levels prevents
serious complications of that disease. Anti-hypertensive agents
may even prevent mental decline, including in people genetically
susceptible to Alzheimer's disease.
Antihypertensive
Categories
Dozens of antihypertensive
drugs are available. They usually fall into the following categories:
- Diuretics,
which cause the body to excrete water and salt.
- Beta-blockers,
which block the effects of adrenaline, thus easing the heart's
pumping action and widening blood vessels.
- ACE inhibitors,
which reduce the production of angiotensin, a chemical that
causes arteries to constrict.
- Vasodilators,
which expand blood vessels.
- Calcium-channel
blockers, which help decrease the contractions of the heart
and widen blood vessels.
A single-drug
regimen can often control mild to moderate hypertension. More severe
hypertension often requires a combination of two or more drugs.
Recommendations
for Specific Antihypertensives in Various Patient Populations
What to prescribe
and who to prescribe it to are questions of on-going debate and
investigation. In general, the following are some recommendations:
For Most Patients without Complicating Conditions. Beta-blockers,
diuretics, or both are usually recommended as first-line treatment
for patients without complications. These agents are inexpensive,
safe, and effective for such people. One analysis of many studies
reported that diuretics were better than beta-blockers on all important
points, including reducing heart attacks, strokes, and mortality
rates. In fact, studies that have reported benefits were generally
reporting on combinations of diuretics and beta-blockers. One study
even suggested that the combination is less effective than diuretics
alone in some people. Of concern, in fact, are studies reporting
an increase in type 2 diabetes in people who take beta-blockers.
(There was some concern that diuretics also carried this risk, but
a 2000 study of 12,550 patients that confirmed a risk for beta-blockers
found no evidence that diuretics posed the same danger.) Results
on ACE inhibitors are so positive that some experts believe they
should be added as first-line agents, particularly in people at
high risk for heart failure.
For Older Adults. Diuretics continue to be the best choice
for most older adults. A 1999 study reported, in fact, that diuretics
may protect against dementia. Combinations may be needed. Because
of a concern for drug interactions, some physicians are reluctant
to give anti-hypertensive drugs to elderly patients with other risk
factors for heart disease. Studies in 2001 reported, however, that
the use of diuretics or beta blockers in this population, including
those with isolated systolic hypertension, lowered their risks for
heart attack, stroke, and heart failure.
For African Americans. Diuretics are also the best choice
for many African Americans, who are more likely to be salt-sensitive
and so respond well to these drugs. It had been widely thought that
African-American patients usually did not respond to ACE inhibitors.
A 2000 report indicated, however, that when taken in higher doses
and when salt is restricted, ACE inhibitors are effective and also
protect the kidneys in this population. (Calcium-channel blockers
are often used in this population, but they do not appear to prevent
either heart or kidney complications and they are very expensive.)
For Patients with Diabetes. Studies are now suggesting the
people with diabetes need to control their blood pressure to 130/85
mm Hg or lower to protect the heart and help prevent other complications
common to both diseases. In general, ACE inhibitors are the first
choice for people with diabetes, since they also appear to protect
the kidneys. In many cases, however, combinations are required to
achieve blood pressure goals. In such cases, low-dose diuretics
or calcium-channel blockers are added as needed.
For Patients with Obesity. Treating hypertension in people
who are obese may present problems. Losing weight is critical, but
some of newer and effective weight-loss agents, such as sibutramine
(Meridia), may actually raise blood pressure. People with obesity
also often have metabolic abnormalities that may be exacerbated
by anti-hypertensive medications. ACE inhibitors and angiotensin
receptor blockers may be helpful in such cases.
For Patients with Isolated Hypertension. Isolated high systolic
pressure is usually treated with a diuretic. A long-acting calcium-channel
blocker may be an alternative, particularly for elderly patients
with diabetes, although some experts believe beta-blockers are still
the best choice even in this group.
For Patients with Heart Failure. People with heart failure
should be given ACE inhibitors and diuretics.
Pregnant Patients. Most women who develop high blood pressure
only during pregnancy (gestational hypertension) are at low risk
for preeclampsia and require no treatment other than monitoring.
Treating pregnant women who have chronic, mild hypertension is probably
not necessary, although no large studies have been done to confirm
this. Many of the standard antihypertensive drugs, particularly
ACE inhibitors, have potentially harmful effects to a fetus. The
beta-blocker atenolol is also associated with adverse effects on
the fetus; studies on other beta-blockers are conflicting. Treatment
for preeclampsia ranges from monitoring to emergency treatments,
depending on severity. It does not respond well to standard drug
treatments. Preventive treatment using magnesium sulfate during
labor is recommended by some experts.
Side
Effects and Problems in Compliance
One of the most
difficult issues that hypertensive patients face, particularly those
with primary hypertension, is that the treatment may make them feel
worse than the disease, which is almost always without symptoms.
Patients face a life-long prospect of taking drugs with unpleasant
side effects, reducing their salt intake, exercising, and watching
their diet. Whatever the difficulties, compliance with a drug and
lifestyle program is worth the effort and the cost. It is very important,
in any case, to rigorously maintain a drug regimen.
Withdrawal
from Antihypertensive Medications
Patients whose
blood pressure has been well-controlled and who are able to maintain
a healthy life style may choose to withdraw from hypertensive medications.
They should do so in a step-down manner (gradual reduction) and
be monitored regularly. Stopping too quickly can have adverse effects,
including serious effects on the heart. The highest success rates
are more likely in those who lose weight and reduce sodium intake
and who are able to control their blood pressure within five years
of an initial diagnosis and treatment with a single agent.
WHAT
ARE THE SPECIFIC DRUG TREATMENTS USED FOR HIGH BLOOD PRESSURE?
Diuretics
For decades,
diuretics, which cause reduction of water and sodium, have been
the mainstays of antihypertensive therapy and are still considered
the first choice by experts, especially for treating the elderly
and African-American patients.
Benefits of Diuretics. Some of the benefits reported on
diuretics include the following:
- Diuretics
significantly reduce the risk for stroke; they may in fact be
the most important anti-hypertensive agent for preventing this
brain attack. They also appear to protect against stroke in
people without hypertension.
- They are
associated with lower risk for heart attack (although this is
not as significant as their protection against stroke).
- They may
also protect against blood clots.
- Diuretics
may help reduce the rate of fractures in elderly people who
have taken them for a long time.
Diuretic Types.
Diuretics come in many brands and are generally inexpensive.
Some need to be taken once a day, others twice a day.
Three primary types of diuretics exist:
- Thiazides.
Thiazides often serve as the basis for high blood pressure treatment,
either taken alone for mild to moderate hypertension or used
in combination with other types of drugs. There are many thiazides
and thiazide-related drugs; some common ones are chlorothiazide
(Diuril), chlorthalidone (Hygroton), indapamide (Lozol), and
hydrochlorothiazide (Esidrix, HydroDiuril).
- Loop diuretics.
Loop diuretics block sodium transport in parts of the kidney;
they act faster than thiazides and have a great diuretic effect.
It is important therefore to control the medication and avoid
dehydration and potassium loss. Loop diuretics include bumetanide
(Bumex), furosemide (Lasix), and ethacrynic acid (Edecrin).
- Potassium
sparing agents. Some potassium-sparing diuretics include amiloride
(Midamor), spironolactone (Aldactone), and triamterene (Dyrenium).
Problems with
Diuretics. The loop and thiazide diuretics deplete the body's
supply of potassium, which, if left untreated, increases the risk
for arrhythmias. Arrhythmias are heart rhythm disturbances that
can, in rare instances, lead to cardiac arrest. In such cases, physicians
will either prescribe lower doses of the current diuretic, recommend
potassium supplements, or use potassium-sparing diuretics either
alone or in combination with a thiazide. Potassium-sparing drugs
have their own risks, which include dangerously high levels of potassium
in people with existing elevated levels of potassium or in those
with damaged kidneys. It should be noted, however, that, in general,
all diuretics are more beneficial than harmful.
Common Side Effects. Common side effects of diuretics are
fatigue, depression, irritability, urinary incontinence, loss of
sexual drive, breast swelling in men, and allergic reactions. Diuretics
can trigger attacks of gout. They may also increase the risk of
gastrointestinal (GI) bleeding. Diuretics may raise cholesterol
level and, used alone, they have no effect on enlarged heart size
(hypertrophy). Arrhythmias can also occur as an interaction between
diuretics and certain drugs, including some antidepressants, anti-arrhythmic
drugs themselves, and digitalis.
Beta-Blockers
Benefits of
Beta-blockers. Beta-blockers have the following benefits for
people with high blood pressure:
- They affect
the force and frequency of heartbeats.
- They slow
certain metabolic processes.
- They ease
the workload of the heart.
They are very
effective in reducing blood pressure and have been associated with
the following positive effects on the heart:
- They are
now well known for reducing deaths from heart disease.
- In one
study, the beta-blocker atenolol (Tenormin) reduced left ventricular
hypertrophy and, when used with the diuretic chlorthalidone,
was found to significantly reduce the risk for heart failure,
particularly in patients at high risk for it.
- Studies
are now finding that certain beta-blockers called nonselective
beta-blockers (such as carvedilol) may improve heart function,
symptoms, and survival in patients with mild to moderate heart
failure.
Beta-blocker
Brands. Many beta-blockers are now available, including propranolol
(Inderal), acebutolol (Sectral), atenolol (Tenormin), betaxolol
(Kerlone), carteolol (Cartrol), metoprolol (Lopressor), nadolol
(Corgard), penbutolol (Levatol), pindolol (Visken), carvedilol (Coreg),
and timolol (Blocadren). The drugs may differ in their effects and
benefits.
Problems with Beta-Blockers. On the downside, studies are
reporting that, when used alone, they may reduce blood pressure,
but they do not reduce mortality rates. And, of concern are studies
reporting an increase of type 2 diabetes in people who take beta
blockers. Because they can narrow bronchial airways and constrict
blood vessels, patients with asthma, emphysema, and chronic bronchitis
should avoid them whenever possible. Some beta-blockers tend to
lower HDL cholesterol (the beneficial cholesterol) by about 10%;
the effect is most marked in smokers.
Common Side Effects. Fatigue and lethargy are the most common
psychologic side effects. Some people experience vivid dreams and
nightmares, depression, and memory loss. Dizziness and lightheadedness
may occur upon standing. Exercise capacity may be reduced. Other
side effects may include coldness in the extremities (that is, legs
and toes; arms and hands), asthma, decreased heart function, gastrointestinal
problems, and sexual dysfunction. If side effects occur, the patient
should call a physician, but it is extremely important not to stop
the drug abruptly. Angina, heart attack, and even sudden death have
occurred in patients who discontinued treatment without gradual
withdrawal.
Angiotensin
Converting Enzyme Inhibitors
Angiotensin converting
enzyme (ACE) inhibitors block the effects of the angiotensin-renin-aldosterone
system, which is thought to have many harmful effects on the heart
and blood vessels. These agents have the following health benefits.
- They may
be very important agents for patients with diabetes. They may
help protect the kidneys and the hearts of these patients, independently
of their effect on blood pressure.
- They may
help prevent changes in the heart muscle cells leading to heart
failure, specifically in reducing enlargement of the left side
of the heart, a major risk factor for heart failure.
- ACE inhibitors
can improve a patient's odds of surviving a heart attack.
Brands.
ACE inhibitors include captopril (Capoten), enalapril (Vasotec),
quinapril (Accupril), benazepril (Lotensin), ramipril (Altace),
perindopril (Aceon), and lisinopril (Prinivil, Zestril).
Problems with ACE Inhibitors. ACE inhibitors are expensive
and, in general, effective only in combination with other anti-hypertensive
agents. Although ACE inhibitors are now recommended for heart failure
patients, of great concern is research suggesting that aspirin (and
other so-called NSAIDs) increases the risk for heart failure
in patients taking ACE inhibitors. NSAIDs are commonly used by patients
with heart disease to prevent heart attacks. Although ACE inhibitors
can protect against kidney disease, they also increase potassium
retention in the kidneys. This increases the risk for cardiac arrest
if levels become too high. Because of this action, they are not
generally given with potassium-sparing diuretics or potassium supplements.
Side effects include an irritating cough, excessive drops in blood
pressure, and allergic reactions. (In some people, the cough is
intolerable. Iron supplements or the drug picotamide may prove to
help reduce the frequency of coughs.) One rare but severe side effect,
granulocytopenia, which is an extreme reduction in white blood cells,
has been observed.
Vasodilators
Vasodilators,
which widen blood vessels, are often used in combination with a
diuretic or a beta-blocker. They are almost never used by themselves.
Representative vasodilators include hydralazine (Apresoline), clonidine
(Catapres, available in tablets or as a skin patch), and Minoxidil
(Loniten). Some of these drugs should be used with caution or not
at all in people with angina or who have had a heart attack.
Calcium-Channel
Blockers
Calcium-channel
blockers, or calcium antagonists, have an immediate effect on reducing
blood pressure. Despite this, studies continue to report that they
are be inferior to the other anti-hypertensive agents in preventing
heart events, stroke, or kidney complications. They are also more
expensive than diuretics or beta-blockers. There is even some evidence
that they pose higher risks for heart attack, heart failure, and
other major adverse cardiovascular events than do other agents.
Some experts now believe they should be used only as a last resort.
Calcium-Channel Blocker Brands. Calcium-channel blockers
approved for high blood pressure include diltiazem (Cardizem, Dilacor),
amlodipine (Norvasc), felodipine (Plendil), isradipine (DynaCirc),
verapamil (Calan, Isoptin, Verelan), nisoldipine (Sular), nicardipine
(Cardene), and nifedipine (Adalat, Procardia). Others under investigation
are lercanidipine (Zanidip) and nitrendipine.
Side Effects. Side effects vary among different preparations.
Most drugs can cause fluid accumulation in the feet, along with
constipation, fatigue, impotence, gingivitis, flushing, and allergic
symptoms. Interactions with foods and drugs also differ depending
on the drug. For example, verapamil interacts with digoxin, but
diltiazem does not. Overdose on many of these agents can cause a
severe drop in blood pressure. Note: Grapefruit and Seville, or
sour, oranges, boosts the effects of calcium-channel blocking drugs,
which are often used for hypertension. Seville oranges are often
used in marmalade or other condiments. (Regular oranges do not appear
to pose any hazard.)
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