Heart Information Center


Introduction
What is Blood Pressure?
What Is High Blood Pressure?
What Causes High Blood Pressure?
Risk Factors - Who Gets High Blood Pressure?
Is High Blood Pressure Serious?
Damage to Body Organs caused by High Blood Pressure
Symptoms of High Blood Pressure
How is High Blood Pressure Diagnosed?
Treatment of High Blood Pressure
  Lifestyle Changes (no medication)
***** High Blood Pressure Medicines
 
Side Effects of Hypertension Treatments
Other Sources of Information

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Introduction

High blood pressure is frequently referred to as the"silent killer". Although elevated blood pressure causes no symptoms in most people it directly kills 35,000 to 40,000 Americans a year and is a major factor in the 400,000 plus deaths each year from heart attacks, congestive heart failure, and stroke. An estimated 50 million Americans (25% of all adults) have high blood pressure. Two-thirds of the population will experience at least mild high blood pressure before the age of 65. Although the majority have mild hypertension, even this condition requires medical attention. Only 20% of American adults have their blood pressure under control. About one-third of patients with high blood pressure are overweight. Anyone who is overweight has a risk for hypertension that is 50% higher than people with normal weight.

Proper detection and treatment of high blood pressure can improve quality of health and delay or prevent many premature deaths in people having hypertension.

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What is Blood Pressure?

Blood pressure is produced by the pumping heart. Most people are familiar with two separate numbers used in measuring blood pressure. In laymen's terms these numbers are referred to as the"top" and "bottom" numbers. Medically speaking blood pressure has a systolic (top number ) measurement and a diastolic (bottom number) measurement. Systolic pressure is the blood pressure created while the heart is contracting (systole). Diastolic pressure is the blood pressure measured when the heart is not contracting (diastole).

Blood pressure measurements reflect the pressure within the artery being measured. Pressure may be different in different arteries of the body. The artery traditionally used for blood pressure measurement is the brachial artery in the arm. Blood pressure does not fall to zero in the arteries when the heart is not contracting due to several factors. The main reason is due to elastic stretch of the arteries. During systole arteries expand slightly (much like a balloon inflates as you blow into it). As the arteries relax (slightly deflate) they continue to propel blood forward just as a deflating balloon releases air in a continuous manner. During diastole the aortic valve closes preventing the flow of blood back into the heart. The heart beats again to repeat this cycle. Steady delivery of blood to body organs is extremely important.

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Optimal blood pressure is less than 120/80 mm Hg (systolic/diastolic). Normal pressure is below 140/90. A person is considered to have hypertension (high blood pressure) if their blood pressure is above 140/90. Any blood pressure above normal should be attended to with appropriate treatments.

Hypertension is divided into four stages: mild (greater than 140/90 but less than 160/100); moderate (less than 180/110); severe (less than 210/120); very severe (greater than 210/120). When the systolic and diastolic numbers are in different categories the measurement in the higher category should be used to determine the severity of hypertension. For example, if systolic pressure is 165 (moderate) and diastolic is 92 (mild), the patient would still be diagnosed with moderate hypertension.

A child's blood pressure is normally much lower than an adult's. Children are at risk for hypertension if blood pressure is greater than:

  • 116/76 for ages 3-5
  • 122/78 for ages 6-9
  • 126/82 for ages 10-12
  • 136/86 for ages 13-15.

High blood pressure is a very important risk factor for heart disease (coronary artery disease). There are other major risk factors as well including family history, smoking, diabetes, and high cholesterol. The effects of these risk factors are additive. A person with all of these risk factors, including high blood pressure, is more likely to develop heart disease than another person with the same blood pressure but no other risk factors. The important point to remember is high blood pressure is not the only risk factor for heart disease and stroke. How a person's blood pressure is treated may depend on other factors in addition to the blood pressure number.

The National Heart Blood and Lung institute has recognized the influence of other risk factors in addition to high blood pressure. High blood pressure is now categorized by risk groups A, B, and C. For example, group A has no risk factors for heart disease or other medical problems; people in this risk group who have mild hypertension would use diet and exercise to try to reduce their blood pressure. Mild hypertension in group C, which covers major risk factors for heart disease, however, would probably require medication.

Blood pressure varies the same way throughout a given day. It is usually highest at work and then drops a bit at home. Pressure is lowest during sleep but suddenly increases at waking.

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What Causes High Blood Pressure?

In over 90% of patients with high blood pressure the physician cannot find a specific cause. This is called essential, or primary, hypertension. Several genetic factors regulating important physiologic processes may interact with environmental influences to produce essential high blood pressure.

Current studies are examining genes that affect a group of hormones known as the angiotensin-renin system, which influences all aspects of blood pressure control, including blood vessel contraction, salt and water balance. Studies suggest that some people with essential hypertension may inherit abnormalities of the sympathetic nervous system, which controls heart rate, blood pressure, and the diameter of the blood vessels. Increased insulin resistance and low levels of a naturally occurring vasodilator (nitric oxide) are also suspected of playing a role in hypertension.

Secondary Hypertension

Secondary hypertension (less than 10% of people with high blood pressure) has identifiable causes, which are usually treatable or reversible. Medical conditions and medications may contribute to secondary hypertension. Medical conditions include:
  • pregnancy
  • liver disease
  • kidney disease
  • adrenal disorders causing excessive production of certain adrenal hormones
  • sleep apnea patients who have disordered breathing while sleeping tend to have higher blood pressure and poorer responses to high blood pressure medication.

Certain prescription and over-the-counter drugs can cause temporary high blood pressure. Medications contributing to secondary hypertension include:

  • Some prescription medications include cortisone, prednisone, estrogen, and indomethacin.
  • Oral contraceptives may increase the risk for high blood pressure, but the risk is very small (41.5 cases per 10,000 people who take birth control pills) and is highest in women using them for more than 6 years.
  • Long term use of nonsteroidal anti-inflammatory drugs (NSAIDs) may cause kidney damage; these drugs can also interfere with treatments for hypertension, including diuretics and beta blockers. Such drugs include aspirin, ibuprofen (Advil, Motrin, Nuprin), indomethacin (Indocin), 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, but they seem to do no harm in people who have brought their blood pressure under control.

Salt

Diets high in salt may speed up hypertension in people as they age. There have been conflicting view in the medical community on how much a high salt diet contributes to hypertension. Between 30 - 50% of people with high blood pressure are salt-sensitive; that is they are particularly vulnerable to the effects of salt on blood pressure. People who are most likely to be very salt-sensitive are overweight, older, and African American. High salt diets in such people can also harm the kidney and brain, even independently of high blood pressure.

Alcohol

An estimated 10% of hypertension cases are caused by excessive alcoholic intake. An analysis of a major study found that those who drank more than three alcoholic drinks a day had higher blood pressure than those who didn't, with heavier drinkers having higher pressure. People who were binge-drinkers had higher blood pressure than people who drank regularly. On the other hand, mild to moderate drinking (one to two drinks a day) seems to have certain benefits, including raising HDL cholesterol levels (high levels of HDL cholesterol are considered good, whereas high levels of LDL cholesterol are considered bad) and reduced risk of heart disease.

Other Causes of Secondary High Blood Pressure

Temporary high blood pressure can result from stress, exercise, and long-term consumption of large amounts of licorice. Exposure to even low lead levels also appears to cause hypertension in adults.

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Risk Factors-Who Gets High Blood Pressure?

Age and Weight

An estimated 50 million Americans (25% of all adults) have high blood pressure. Two-thirds of Americans will experience at least mild high blood pressure before the age of 65. Although the majority have mild hypertension, even this condition requires medical attention. Only 20% of American adults have their blood pressure under control. About one-third of patients with high blood pressure are overweight. Anyone who is overweight has a risk for hypertension that is 50% more than people with normal weight. In fact, the increase in blood pressure as one ages may be due primarily to weight gain. (This is true particularly in America; in other cultures old age does not necessarily coincide with weight gain--or high blood pressure.) Children and adolescents who are obese and babies who are underweight at birth are at greater risk for high blood pressure when they reach adulthood.

Gender and Ethnicity

Women under 60 are 50% to 75% less likely to have hypertension than men of the same age. Between ages 50 and 60, 40% of white men and 30% of white women have high blood pressure. In African Americans of the same age groups over half of men and slightly less than half of women have hypertension. After age 60, half of white men and women have high blood pressure, but the rate in African Americans is 60% in men and leaps to 80% in women. Both whites and African Americans in the Southeast have a higher incidence of hypertension and stroke than people living in other parts of the country. African Americans tend to have a greater sensitivity to salt than others, although researchers have not found that this trait fully explains the higher incidence for hypertension. The combination of high blood pressure and insulin resistance (type II diabetes)is more common in African Americans, Hispanics, and Pima Indians than in whites. It should be noted that a recent study of African villagers whose diets were high in fish had only a 3% rate of high blood pressure.

Genetic Factors

Some experts believe that essential hypertension may be inherited in 30% to 60% of cases, although several genes, not just one, are probably involved. It is difficult to differentiate between genetic and environmental influences, even in studies of identical twins.

Cholesterol and Stress

About 40% of people with high blood pressure also have high cholesterol levels, although any causal relationship remains unclear. Stress may play a role in this association; in one study people with high cholesterol levels experienced a steep increase in high blood pressure when given a mental stress test; those with normal cholesterol levels had only a modest increase. When the high-risk group lowered their cholesterol intake, their blood pressure dropped to normal levels during stressful situations. This finding should encourage physicians to test for heart disease risks, particularly unhealthy cholesterol levels, in people with so-called white-coat hypertension--a phenomenon that causes high blood pressure in the physician's office despite normal blood pressure at home.

Emotional Disorders

A number of studies have linked chronic stress, depression, and anxiety with high blood pressure in both men and women. People who are anxious or depressed may have over twice the risk for high blood pressure than those without these problems. It is not clear whether these mood disorders contribute to high blood pressure due to some physiologic effect on blood vessels or if they may lead to behaviors, such as weight gain or alcohol abuse, which are also risk factors for hypertension. Stress caused by discrimination may play a role in the high rate of hypertension in African Americans; in one study, those who experienced discrimination but did not report it suffered higher blood pressure than those who challenged it. Anger does not appear to predict high blood pressure.

Other Factors

People who experience sleep apnea, a disorder in which breathing halts briefly but repeatedly during sleep, also have a higher incidence for hypertension. Many experts believe that a causal relationship exists between the sleep disorder and high blood pressure. Seasonal changes may influence variations in blood pressure, with hypertension increasing during cold months and declining during the summer. This seasonal effect is particularly high in smokers. While cold may narrow blood vessels, another study showed that lack of light was associated with higher blood pressure. A recent study reported that people with normal resting blood pressure that increases to abnormally high levels during treadmill exercises may be at risk for essential hypertension. Oral contraceptives, even low doses, may increase the risk for high blood pressure in African American women.

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How Serious Is High Blood Pressure?
High blood pressure killed over 35,000 Americans in 1992 and was a major contributor to deaths from stroke, heart attack, and heart failure. The death rate from hypertension declined by 8.6% between 1982 and 1992. However, it is still particularly deadly in African Americans; an estimated 30% of deaths in men and 20% of deaths per year in women who are African Americans are attributed to hypertension.

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Damage to Other Organs

Hypertension can cause certain organs to deteriorate over time. People who do not control their blood pressure die earlier than people who control their blood pressure. High blood pressure contributes to 75% of all strokes and heart attacks. Compared with normal individuals, hypertensive people can have as high as ten times the risk of stroke and five times the risk of a heart attack depending on the severity of the hypertension. The risk for developing congestive heart failure is also significantly higher with high blood pressure. People whose high blood pressure has caused left ventricular hypertrophy (a thickening of the muscles on the left side of the heart causing enlargement) remain at risk for strokes, heart attacks, sudden death, and heart failure even after their blood pressure is under medical control. High blood pressure causes 30% of all cases of kidney failure that require dialysis and transplant operations. This rate is second only to diabetes. African Americans with high blood pressure are at even higher risk for kidney failure than people in other population groups with hypertension.

Sexual Dysfunction

Some form of sexual dysfunction occurs in 17% of hypertensive men. It is often caused by medications that treat high blood pressure, but there are indications that the disorder itself may impair sexual function. Impotence related to hypertension is treatable. A study found that women with high blood pressure, regardless of medications, found it difficult to achieve sexual satisfaction and had impaired vaginal lubrication.

Mental Deterioration

High blood pressure may accelerate age-related shrinkage of the brain. Chronic high blood pressure is associated with mental deterioration, especially short-term memory and attention. A study has found that middle-age people with high systolic blood pressure are at higher risk for poor mental function in later life; the higher the blood pressure the greater the risk. Increased blood pressure in elderly men is also associated with a higher risk for Alzheimer's and dementia.

Pregnancy and Preeclampsia

Severe, sudden high blood pressure in pregnant women caused by a condition called preeclampsia can be very serious for both mother and child. It occurs in up to 10% of all pregnancies, usually in the third trimester (last three months) of a first pregnancy, and resolves after delivery. Symptoms and signs of preeclampsia include protein in the urine and swollen ankles. 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.

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Hypertension has been called the "silent killer", because it usually produces no symptoms. It is important for anyone with risk factors to have their blood pressure checked regularly and to make appropriate lifestyle changes. Following these recommendations is important for individuals who have overall high-normal blood pressure, mild or above systolic pressure with normal diastolic, family histories of hypertension, are overweight, or are over forty years old.

Untreated hypertension increases slowly over the years. 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 lifethreatening condition and must be treated immediately.

Symptoms may include:

  • Drowsiness, confusion, headache, nausea, and loss of vision.

Hypertensive individuals should call a physician immediately if these symptoms appear.

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How is High Blood Pressure Diagnosed?

Medical History

If hypertension is suspected, the physician should obtain the following information:

  1. Family and personal medical history, especially high blood pressure, stroke, heart problems, kidney disease, or diabetes;

  2. Risk factors of heart disease and stroke, including tobacco use, salt intake, obesity, physical inactivity, and unhealthy cholesterol levels;

  3. Any medications--both prescription and nonprescription--being taken;

  4. A review of symptoms that might indicate secondary hypertension, such as headache, heart palpitations, excessive sweating, muscle cramps or weakness, or excessive urination; and

  5. Any emotional or environmental factors that could affect blood pressure.

Physical Examination

Almost all physical exams include blood pressure measurement. An inflatable cuff is placed around the arm, and the person taking the blood pressure listens with a stethoscope over the artery. If high blood pressure is present or suspected, the physician or health professional should take two or more measurements separated by two minutes with the patient sitting or lying down, as well as one taken after the patient has been standing for two minutes. Patients should not smoke or drink caffeinated beverages within 30 minutes of the measurement.

Although this test has been used for nearly 100 years, inaccurate results can occur in certain situations. A person who has recently exercised or a heavy smoker who has not smoked for awhile can have a temporarily low pressure reading. Temporary high pressure can result from an arm cuff that is too small, talking during the test, or from having recently eaten foods that raise blood pressure. Anxiety can cause a person's blood pressure to be elevated in the doctor's office while it is normal at home. This is known as "White Coat Hypertension". Home monitoring is important to avoid unnecessary treatment in patients whose pressure returns to normal after leaving the doctor's office. Some people initially suspected of only having "White Coat Hypertension" develop true hypertension. Persons with very severe high blood pressure or those exhibiting any evidence of organ damage due to hypertension should consider drug therapy immediately. An individual with mild to moderate hypertension found during a first examination and who has no evident organ damage should be retested at least twice over several weeks. An average of all the measurements will be considered in the diagnosis of hypertension. People with normal blood pressure should be rechecked every two years and those with high normal pressure one year after. Anyone whose blood pressure is above high normal should be evaluated as soon as possible for organ damage and possible medications to reduce the pressure.

Laboratory Tests

If a physical examination indicates hypertension, additional laboratory tests may determine whether it is secondary hypertension (high blood pressure caused by another disorder) or essential hypertension (no other disorder is present). The physician might also order tests to uncover organ damage due to hypertension. These tests include a complete blood count, urinalysis, and measurements of potassium, blood urea nitrogen, fasting blood glucose, serum cholesterol, and serum uric acid. An electrocardiogram (ECG) may also be performed.

Home Tests

Many home tests are available for checking blood pressure between doctor visits. 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 as accurate as a stethoscope. A physician may fit a patient with 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, including white-coat hypertension, or show resistance to drug therapy. Some physicians feel that such monitoring is not worth the expense and that electronic home tests that print out a record for the doctor are more cost effective and very reliable. Devices that take the pressure from the finger can be very inaccurate.

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Life Style Changes (no medication)

Weight Loss 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.Many people who are overweight and hypertensive can bring their blood pressure to normal with only modest weight loss. Systolic blood pressure may decrease by 1-2 points for each pound lost while diastolic pressure may drop 1/2 to 1 point for each pound lost. Weight loss is extremely difficult for many people. It is important to realize that a 10 to 20 pound weight loss in a person who is 50 pounds overweight may not make them "thin" but it may return their blood pressure to normal. It is also important to realize that not all people who are overweight or obese have high blood pressure.

Useful Foods A recent study found that a varied diet low in saturated fat, rich in fruits and vegetables, and with modest amounts of protein significantly lowered blood pressure; after eight weeks, systolic pressure dropped by 11.4 mmHg and diastolic by 5.5 mmHg. The diet, known as Dietary Approaches to Stop Hypertension (DASH) is now recommended as an important step in managing blood pressure. Such a dietary balance is, in any case, important for fighting other health problems, including coronary artery disease and cancer. Although one study found that diets high in protein were associated with lower blood pressure, it was not clear whether the protein was derived from meat, fish, dairy, or vegetable sources, and it should be noted that high protein diets may put people with diabetes at risk for kidney disease. Eating fish appears to benefit both blood pressure and cholesterol levels. Vegetables are very important, with those rich in magnesium and potassium of particular benefit for patients with hypertension. Such foods include most fruits, many vegetables (especially, carrots, spinach, celery, alfalfa, mushrooms, lima beans, potatoes, avocados, broccoli), chicken, liver, and milk. Many of these foods are also high in fiber, which is protective against many diseases. Garlic appears to benefit blood pressure, perhaps by affecting mechanisms that keep blood vessels elastic and healthy. It should be noted that grapefruit (but not other citrus fruits) boosts the effects of calcium channel blocking drugs used for hypertension.

Salt Restriction Salt restriction is important for reducing blood pressure in those who are salt-sensitive and should be attempted in all people with high blood pressure to detect those patients who are salt sensitive. Salt restriction is important for elderly people--even those whose blood pressure is only in the upper normal range, which still puts them at risk for stroke. Restricting salt also enhance the benefits of certain antihypertensive drugs by reducing potassium loss, and may help protect against kidney disease in patients who are also taking calcium-blocker drugs. People with hypertension should aim for a maximum of 2,000 mg salt intake; even people without hypertension should reduce salt intake to 2,400 mg per day or less. Simply eliminating table and cooking salt can be beneficial. Salt substitutes, such as Cardia, containing mixtures of potassium, sodium, and magnesium are now available but are costly. It should be noted that because about 75% of the salt in people's diets comes from processed or commercial foods, the benefits of table-salt substitutes are likely to be limited. 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.

Potassium, Calcium, and Magnesium Studies have indicated that potassium deficiencies, increase the risk for high blood pressure, but it has not been clear whether taking a potassium supplement would be useful for preventing or treating high blood pressure. The recommended goal is 3,500 mg of potassium a day. Excess potassium level, however, can cause abdominal distress, muscle weakness, and, in rare cases, dangerous heart events. Although some people, such as those taking certain diuretics, may require supplements, certain patients should be 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. Most people should obtain this mineral from potassium-rich foods that include potatoes, avocados, bananas, nonfat milk products, red beans, oranges, prunes, and cantaloupes.

Calcium regulates the tone of the smooth muscles lining blood vessels, and large studies have found that people who have sufficient dietary calcium have lower blood pressure than those who don't. Taking calcium tablets exceeding the recommended daily allowance of 800 to 1,200 mg, however, has very little additional effect on blood pressure in women and African American men and none for white men. Extra calcium appears to be useful for lowering blood pressure only in people who are also salt-sensitive. A 1996 study suggested that calcium supplements might reduce the risk for preeclampsia in pregnant women, but follow-up studies did not confirm this benefit. (Pregnant and postmenopausal women often need extra calcium, however, to prevent bone loss.)

One study has indicated that magnesium supplements help to decrease blood pressure. It is important to remember, though, that no major studies have been done on long-term benefits or risks of magnesium supplements.

Caffeine Intake, Alcohol, and Smoking Caffeine causes a temporary increase in blood pressure, but is not thought to be harmful, particularly in people with normal blood pressure. Caffeine may, however, have a stronger and longer-lasting effect on the blood pressure of people with existing hypertension. Drinking coffee increases excretion of calcium, which increases the risk for high blood pressure, so anyone who drinks coffee should maintain an adequate calcium intake. Smoking poses risks for a wide range of diseases, and one study reported that smokers have blood pressures up to 10 points higher than nonsmokers. Although moderate drinking (one to two drinks per day) of alcohol protects against unhealthy cholesterol, high alcohol consumption raises blood pressure levels.

Exercise

Even moderately intense physical activity can reduce blood pressure. An additional benefit of exercise is weight loss, which is a key factor in reducing blood pressure. Studies have shown that regular activity, particularly aerobic exercises, helps to reduce mild to moderate hypertension. In one study African-American men with severe hypertension who engaged in moderately intense aerobic exercise using a stationary bike three times a week not only reduced their diastolic pressure but also reduced left ventricle hypertrophy after about four months. One study showed that even exercise that does not result in weight loss or have any aerobic benefits still significantly reduces blood pressure in postmenopausal women. As little as 35 minutes of walking three times a week can help lower blood pressure, but 20 to 30 minutes of daily brisk walking or other aerobic exercise is more likely to help.

Intensive aerobic exercises, such as running or biking, may lead to so-called athlete's heart, which, like hypertrophy caused by high blood pressure, is muscular enlargement of the heart. Unlike the disease-caused condition, however, this muscular enlargement is not associated with heart problems and regresses when training stops. Isometric workouts, such as snow shoveling or weight lifting, tend to stress the heart and raise blood pressure for a brief period. Such intense isometrics can cause cardiac death, and one major study found that sedentary people who throw themselves into a grueling workout increase the risk of heart attack by 107 times. Two small studies found that people with very mild hypertension who exercised with a hand-grip device for a few weeks achieved lower blood pressure, which increased after the subjects stopped exercising. In all cases, but particularly before strenuous exercise, it is very important to warm up in order to ease the increase in blood pressure. No person with high blood pressure should start an exercise program without consulting a physician. Before exercising, no one with hypertension should drink caffeinated beverages, which increase heart rate, the workload of the heart, and blood pressure during physical activity. Certain antihypertensive medications can interfere with exercise capacity. Diuretics decrease body fluid and may result in fluid imbalances, particularly in hot weather. It is important to boost potassium intake if this type of drug is being taken. Beta blockers inhibit adrenaline and may cause fatigue and loss of endurance during exercise. ACE inhibitors and 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.

Stress Reduction and Psychologic Therapy

Emotional factors or psychologic stress are possible precursors to hypertension. A recent study found that 73% of patients with mild to moderate hypertension who had cognitive-behavioral therapy were able to reduce their medication after 6 weeks; after 12 months, 55% required no medication. In another study, a technique called transcendental meditation (TM), a simple relaxation method that involves silent repetition of a single sound was shown to be effective in reducing blood pressure .

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What Are the Drug Treatments for High Blood Pressure?

General Guidelines for Drug Therapy

Research now suggests that aggressive drug treatment of long-term high blood pressure can significantly reduce the incidence of death from heart disease and other causes in both men and women. If patients have mild hypertension and no heart problems, then lifestyle changes may suffice if carried out with determination. For more severe hypertension or for mild cases that do not respond to changes in diet and lifestyle within a year, drug treatment is usually necessary. All drugs used have side effects, some distressing, and ongoing compliance is difficult. A major study found, however, that people taking blood pressure drugs did not experience any greater decline in the general quality of life or daily functioning over five years than did people who were not on blood pressure medication. In all cases, healthy lifestyle changes must accompany any drug treatment.

A single-drug regimen can often control mild to moderate hypertension. More severe hypertension often requires a combination of two or more drugs. Prolonged-release drugs are being developed so that they are most effective during early morning periods, when patients are at highest risk for heart attack or stroke.

One study showed that to reduce mortality rates, the goal of treatment should be a systolic pressure of less than 134 mm Hg for men and less than 149 for women and a diastolic pressure of less than 95 for both. It should be noted, though, that when people with moderate to severe diastolic hypertension reduce their blood pressure to 90 or less using drugs, they appear to have a higher risk for heart problems. Those with naturally low diastolic pressures do not have this risk.

Dozens of antihypertensive drugs are available. They usually fall into the following categories:

(1) Diuretics, which cause the body to excrete water and salt;

(2) ACE inhibitors, which reduce the production of angiotensin, a chemical that causes arteries to constrict;

(3) Beta-blockers, which block the effects of adrenaline, thus easing the heart's pumping action and widening blood vessels;

(4) Vasodilators, which expand blood vessels; and

(5)Calcium channel blockers, which help decrease the contractions of the heart and widen blood vessels.

As first-line treatment experts recommend beta blockers or diuretics, which are inexpensive, safe, and effective, for most people with hypertension without complicating problems.

Other drugs or combinations are now recommended for specific problems:

  • ACE inhibitors should be used as the first-line treatment for people with diabetes and kidney damage.

  • Heart attack survivors are usually given beta blockers and sometimes ACE inhibitors to prevent a second attack.

  • People with heart failure should be given ACE inhibitors and diuretics; specific drugs in these classes may be particularly beneficial for these patients because they reduce left ventricle hypertrophy. One study showed that diuretics are effective for preventing heart failure after a heart attack.

  • Because they have a higher risk for salt sensitivity, African Americans are usually prescribed diuretics. Isolated high systolic pressure is treated with a diuretic; one study found that when a beta blocker was added the risk of heart failure was cut by half in patients with this condition.

 

Experts also now warn against taking short-acting calcium channel blockers, which may increase the risk of heart problems and even death. Some studies are also suggesting that calcium channel blockers increase the risk for certain cancers, including breast cancer, and also for bleeding during surgery. Some physicians have also been concerned about the long-term effects of antihypertensive drugs on mental processes.

Diuretics

For decades, diuretics, which cause reduction of water and sodium, have been the mainstays of antihypertensive therapy. Diuretics have reduced the incidence of stroke by a significant 40% and, to a lesser degree (about 16%), the incidence of hypertension-related heart attacks. They also may protect against blood clots. Diuretics come in many brands and are generally inexpensive. Some need to be taken once a day, some twice a day. A diuretic used as initial single therapy is particularly effective in elderly and African-American patients. Diuretics may also help reduce the rate of fractures in elderly people who have taken them for a long time. It has been thought that long-term use of diuretics can be harmful to patients with diabetes; one large study, however, reported that a low-dose diuretic reduced the risk of major heart disease with few adverse effects in older patients who had type 2 diabetes and isolated systolic hypertension. Experts believe that diuretics should be the first line of therapy for such patients.

Three primary types of diuretics exist:

  1. thiazides
  2. loop diuretics
  3. potassium sparing agents.

  • 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), and hydrochlorothiazide (Esidrix, HydroDiuril).

  • 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 burmetanide (Bumex), furosemide (Lasix), and ethacrynic acid (Edecrin). The loop and thiazide diuretics deplete the body's supply of potassium, which can cause arrhythmias--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 diuretics include amiloride (Midamor), spironolactone (Aldactone), and triamterene (Dyrenium). Studies indicate that people who take a potassium-sparing diuretic with a low-dose thiazide have a lower risk for cardiac arrest than those taking either a beta-blocker or thiazide alone. Potassium-sparing drug have their own risks, which include dangerously high levels of potassium in people with damaged kidneys or who have a high potassium intake from other sources.

It is important to stress that, in general, all diuretics are more beneficial than harmful. (Arrhythmias can also occur as an interaction between diuretics and certain drugs, including some antidepressants, antiarrhythmic drugs themselves, and digitalis.) 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 and may raise cholesterol level; they have no effect on heart size.

Beta and Alpha Blockers

Beta blockers prevent certain receptors in the heart from taking up chemicals (adrenaline type) responsible for the force and frequency of heart beats. As a result they ease the workload of the heart, and reduce pressure. They are very effective, and currently recommended along with or instead of diuretics as initial treatment. In studies, beta blockers have been associated with a lower risk for a second heart attack or sudden death after a first heart attack. These drugs are not as effective as ACE inhibitors in people with or at risk for kidney disease. Because they can narrow bronchial airways and constrict blood vessels, patients with asthma should avoid them whenever possible. 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), and timolol (Biocadren). The drugs may differ in their effects and benefits. Carvedilol (Coreg), which is a mild beta blocker with some vasodilating properties has been found to improve very severe heart failure. It also appears a better effect on insulin sensitivity than other beta blockers and so may prove to be a good choice for people with diabetes. A similar drug, bucindol, is in development. Atenolol has been found to reduce left ventricular hypertrophy and, when used with the diuretic chlorthalidone, was found to significantly reduce the risk for heart failure, particular in patients at high risk for it.

Some beta blockers tend to lower HDL cholesterol (the beneficial cholesterol) by about 10%; the effect is most marked in smokers. Fatigue and lethargy are the most common psychologic side effects. Some people experience vivid dreams and nightmares, depression, and memory loss. Exercise capacity may be reduced. Other side effects may include cold extremities, asthma, decreased heart function, gastrointestinal problems, and impotence. 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 have successfully battled all types of hypertension. Many brands are available that are similar in efficacy and safety, as well as in price, which, unfortunately, is high. ACE inhibitors include captopril (Capoten), enalapril (Vasotec), quinipril (Accupril), benezepril, and lisinopril (Prinivil, Zestril). ACE inhibitors are recommended as first-line treatment for people with diabetes and kidney damage, for some heart attack survivors, and for patients with heart failure when taken with diuretics. Captopril has also been found to reduce left ventricular hypertrophy. African-American patients usually do not respond well to ACE inhibitors unless they are combined with diuretics. Although these drugs are expensive, one study demonstrated that enalapril decreased the risk of death by 18% and reduced hospital visits, saving over $1,500 per patient over a 40-month period. Side effects are uncommon but may include an irritating cough, excessive drops in blood pressure, and allergic reactions. A recent study found that the drug picotamide can help reduce the frequency of coughs. Although ACE inhibitors can protect against kidney disease, they also cause the kidneys to retain potassium, which can cause cardiac arrest if levels become too high. Because of this action, they are not generally given with potassium-sparing diuretics or potassium supplements. One rare but severe side effect--granulocytopenia--has been observed, which is an extreme reduction in white blood cells; this can be minimized with lower dosages.

Vasodilators

Vasodilators, which widen blood vessels, are often used in combination with a diuretic or a beta blocker. Representative vasodilators include hydralazine (Apresoline), prazosin (Minipress), clonidine (Catapres--available in tablets or as a skin patch), and Minoxidil (Loniten). 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

In spite of a number of studies indicating severe problems with certain calcium channel blockers and that other drugs, particularly beta blockers, are equally or more effective, prescriptions for calcium channel blockers continue to increase. Calcium channel blockers include diltiazem (Cardizem, Dilacor), amlodipine (Norvasc), verapamil (Calan, Verelan), nisoldipine (Sular), nicardipine (Cardene), nifedipine (Adalat, Procardia), isradipine (DynaCirc), mibefradil (Posicor), lercanidipine (Zanidip), felodipine (Plendil), and nitrendipine. These drugs are expensive but may be useful for people who cannot take beta blockers and for people with heart rhythm disorders. Sustained-release calcium channel blockers provide stable and persistent lower blood pressure. Side effects vary among different preparations, and may include fluid accumulation in the feet, constipation, fatigue, impotence, gingivitis, flushing, and allergic symptoms. Grapefruit juice appears to boost the effects of these drugs in some people. Newer drugs, such as lercanidipine may reduce or avoid many of these side effects.

A number of serious questions have been raised over the use of calcium channel blockers. Of major concern is an increased risk of death and serious heart events from abrupt drops in blood pressure in people taking short-acting forms (those taken three times a day) of the calcium channel blocker nifedipine. Experts now recommend that short-acting nifedipine be taken with great caution, if at all. Although most studies on long-acting forms of calcium channel blockers or other short acting forms, including diltiazem, do not report an increased risk for heart events, a recent study found that patients with type 2 diabetes who took nisoldipine, a long-acting calcium channel blocker, had a significantly higher number of heart attacks than those on an ACE inhibitor. Other worrisome studies have pointed to a higher rate of cancer in those taking calcium channel blockers compared to people taking other antihypertensive medications. One reported more than double the risk for breast cancer in women taking calcium channel blockers, particularly if they were taking short-acting forms along with estrogen therapy. Studies have found a significantly increased risk for blood loss during surgery in patients taking these drugs. Another study found changes in brain tissue on scans of people who had taken calcium channel blockers. No one currently taking any calcium channel blocker should stop taking it abruptly, because such action could dangerously increase the risk of high blood pressure. Patients who are concerned should consult with their physician about alternative medications. Even long-acting calcium channel blockers should be used with caution or not at all by people who have had a recent heart attack, who have unstable angina, or who have or at risk for congestive heart failure. Of some encouragement are studies that have found that the negative effects of calcium channel blockers, even nifedipine, are reduced when they are taken with a beta blocker or diuretics.

Other Drugs

Drugs known as angiotensin II receptor antagonists, including losartan, candesartan cilexetil, and valsartan (Diovan), have benefits similar to ACE inhibitors and may have fewer or less severe side effects, including coughing. They may also have positive effects on blood vessels. Labetalol (Normodyne, Trandate) is an alpha-beta blocker and is useful for hypertensive patients who also have angina. Alpha blockers, which include terazosin (Hytrin) and doxazosin (Cardura), are also effective against high blood pressure, particularly in men who also have benign prostatic hyperplasia. Doxazoin reduces systolic pressure and may improve cholesterol levels.

Treatment During Pregnancy

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. Those with more severe hypertension, however, should be treated, usually with methyldopa or labetolol. Many of the standard antihypertensive drugs, particularly ACE inhibitors, have potentially harmful effects to a fetus. Women who have taken ACE inhibitors before pregnancy will not endanger the fetus if they discontinue therapy during the first trimester. Atenolol is also associated with adverse effects on the fetus; studies on other beta blockers are conflicting. No significant or long-term studies have been conducted on pregnant women using calcium channel blockers. 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.

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Side Effects of Hypertension Treatment

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 symptomless. Patients face a lifelong prospect of taking drugs with unpleasant side effects, reducing their salt intake, exercising, and watching their diet. Many drugs that treat high blood pressure impair sexual function, for example, although this is immediately reversible once the drug is stopped. Whatever the difficulties, compliance with a drug and lifestyle program is worth the effort and the cost.

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Other Sources of Information About High Blood Pressure?

National Heart, Lung, and Blood Institute Information Center
P.O. Box 30105 Bethesda, MD 20824-0105
301-251-1222
The web site also includes the DASH diet.

American Heart Association
7272 Greenville Ave..- Dallas, Texas 75231-4596
214-373-6300 or 800-242-8721

This is a primary source of information for heart problems. They are very responsible and will send free pamphlets and reading material, including useful diet information and locations of local representatives.

Medic Alert
2323 Colorado Ave. , Turlock, CA 95380
This organization provides bracelets or neck chain emblems with critical personal medical information. Also keep computerized medical records (call 800-432-5378).

NOAH (New York Online Access to Health)
A joint effort between various public New York institutions NOAH seeks to provide high quality full-text health information for consumers that is accurate, timely, relevant and unbiased. NOAH currently supports English and Spanish. Covers lots of health topics.

On the Internet
Site dedicated to high blood pressure (http://www.bloodpressure.com)
Well written, easy to understand. Some promotion of commercial products.

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Doctors Corner INternet Group, Inc. 1997-2004

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