• Home

Home > Medical Reference > Patient Education

• Highlights
• Introduction
• Diagnosis
• Causes
• Risk Factors
• Complications
• Symptoms
• Treatment
• Lifestyle Changes
• Medications
• Classes of Medications
• Resources
• References

High blood pressure

Description

An in-depth report on the causes, diagnosis, treatment, and prevention of high blood pressure.

Alternative Names

Hypertension

Lifestyle Changes

Healthy lifestyle changes are an important first step for lowering blood pressure. Current guidelines recommend that people should:

• Exercise at least 30 minutes a day
• Maintain normal weight
• Reduce salt intake
• Increase potassium intake
• Limit alcohol consumption
• Consume a diet rich in fruits, vegetables, and low-fat dairy products while reducing total and saturated fat intake. (The DASH diet is one way of achieving such a dietary plan.)

DASH Diet

The DASH diet (Dietary Approaches to Stop Hypertension) is proving to help lower blood pressure. Results are sometimes seen within a few weeks. Restricting sodium improves results. The diet appears to have antioxidant effects and may help lower LDL cholesterol levels, although beneficial HDL levels also decline.

This diet not only is 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.

Dietary recommendations:

• Reduce saturated fat (but include calcium-rich dairy products that are non- or low-fat).
• When choosing fats, select monounsaturated oils, such as olive or canola oils.
• Choose whole grains over white flour or pasta products.
• Choose fresh fruits and vegetables every day. In one study, people who increased their intake of fruits and vegetables experienced a drop in blood pressure after 6 months. Many of these foods are rich in potassium, fiber, or both, possibly helping lower blood pressure.
• Include nuts, seeds, or legumes (dried beans or peas) daily.
• Choose modest amounts of protein (preferably fish, poultry, or soy products).

Slight changes to the DASH diet might help further lower blood pressure, as well as improve cholesterol and lipid levels. Researchers reporting in the Journal of the American Medical Association and at the 2005 American Heart Association meeting said that replacing some carbohydrates in the DASH diet with more protein (from plant sources) or monounsaturated fats may help further reduce heart disease risk factors.

Salt Restriction

A combination of the DASH diet and salt restriction is extremely effective in reducing blood pressure. Reducing sodium may also help protect against heart failure. People with normal blood pressure should consume no more than 2,400 milligrams (about one teaspoon) of sodium each day. People with blood pressure should consume much less. (Patients should consult their doctor on individual recommendations for salt intake.) The following higher-risk groups should take particular measures to restrict salt:

• People at Risk for Salt-Sensitivity. About half of people with hypertension have blood pressure that reacts significantly to salt. Such people are known to be salt-sensitive . Groups at particularly high risk for salt-sensitivity include African Americans, the elderly, and people with diabetes. Even people with normal blood pressure can be salt-sensitive . High-salt diets in anyone who is salt-sensitive may harm the heart, kidneys, and brain and increase the risk for death, regardless of blood pressure. 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. Reducing sodium can also help lower the risk of heart disease and stroke in people who are overweight. 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 many standard anti-hypertensive drugs by reducing potassium loss, and may help protect against kidney disease in patients who are also taking calcium-blocker drugs. A low-salt diet can also increase the chances for being able to stop such medications.

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. In any case, 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

Evidence strongly indicates that a potassium-rich diet can help achieve healthy blood pressure levels, and that potassium supplements can lower systolic blood pressure by 1.8 m Hg and diastolic blood pressure by 1 mm Hg. Some evidence suggests that a potassium-rich diet can reduce the risk of stroke by 22 - 40%. Current expert guidelines support the use of potassium supplements or enough dietary potassium to achieve 3,500 mg per day for people with normal or high blood pressure (who have no risk factors for excess potassium levels). This goal is particularly important in people who have high sodium intake.

The best source of potassium is the fruits and vegetables that contain them. Some potassium-rich foods include bananas, oranges, pears, prunes, cantaloupes, tomatoes, dried peas and beans, nuts, potatoes, and avocados.

Excess potassium can cause abdominal distress, muscle weakness, and, in rare cases, dangerous heart events. Some people should be particularly cautious about excess potassium, including those with conditions, such as diabetes or kidney disease, that increase potassium levels. People who take medications, such as ACE inhibitors or potassium-sparing diuretics that limit the kidney's ability to excrete potassium, should not take potassium supplements.

Caffeine, Alcohol, and Smoking

Smoking. Everyone should quit smoking.

Alcohol. People who drink alcohol should do so in moderation. Men with hypertension should limit their intake to no more than one or two drinks a day, and women and lighter people should drink less.

Caffeine Drinks. Coffee drinking is associated with small increases in blood pressure, but the risk is very small in people with normal blood pressure. People with existing hypertension should avoid caffeine altogether.

Other Dietary Considerations

Fiber . Fiber supplementation can help reduce blood pressure levels. It may take up to 8 weeks to achieve the maximum benefit.

Folate . Increasing folate (a B vitamin) intake to more than 800 mcg/day can help reduce blood pressure, particularly for younger women (under age 46). Dietary sources of folate include citrus fruits, leafy green vegetables, beans, and grain products. Folate helps to reduce homocysteine levels.

Fish Oil and Omega 3 Fatty Acids. Omega 3 fatty acids (docosahexaenoic and eicosapentaneoic acids) are found in oily fish. Studies indicate that they may have specific benefits for many medical conditions, including hypertension. They appear to help keep blood vessels flexible and may help protect the nervous system. Fatty acids are also available in supplements, but their long-term effects on blood pressure are unknown.

Calcium. Calcium regulates the tone of the smooth muscles lining blood vessels. 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. The effects of extra calcium on blood pressure, however, are mixed, with some even showing higher pressure.

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.

Antioxidant Supplements. Antioxidants are substances that help the body eliminate oxidants, (also called 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. Vitamin C may have specific benefits for hypertension by preventing dangerous effects on nitric acid, the substance that keeps arteries flexible.

Weight Loss

In people who are overweight, even modest reductions in weight, particularly in the abdominal area, can immediately reduce blood pressure. 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 are long-lasting.

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.

Experts recommend at least 30 minutes of exercise on most -- if not all-days. In one study, moderate exercise (jogging two miles per 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 also 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.

High-intensity exercise may not lower blood pressure as effectively as moderate intensity exercise and may be dangerous in people with hypertension.

Negative Effects. Each year an estimated 75,000 heart attacks (5% of all heart attacks) occur after heavy exertion, leading to 25,000 deaths. Older people and those with uncontrolled hypertension or other serious medical conditions should be cautious when exercising. 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 anti-hypertensive 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 take drugs that interfere somewhat with exercise capability should still adhere to an exercise program and consult a doctor on how best to balance medications with exercise.

Good Sleep Habits

Certain sleep disorders, especially sleep apnea, are associated with hypertension. Even chronic, insufficient sleep may raise blood pressure in patients with hypertension, placing them at increased risk of heart disease and death. 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, (particularly sleep apnea), may want to consult a sleep expert. Patients with hypertension who 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.

Stress Reduction and Psychologic Considerations

Improving mood or relieving stress may be helpful. The following studies suggested possible benefits:

• Stress reduction programs that use cognitive-behavioral therapy may reduce blood pressure.
• 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.
• A simple relaxation technique called transcendental meditation (TM), which involves silent repetition of a single sound, was associated with lower blood pressure.

Treating stress cannot cure medical problems. Stress management programs are not a substitute for standard medical treatments, but can be a very important component of a lifestyle plan.

• Review Date: 4/14/2006
• Reviewed By: Harvey Simon, MD, Associate Professor of Medicine, Harvard Medical School; Physician, Massachusetts General Hospital.

A.D.A.M., Inc. is accredited by URAC, also known as the American Accreditation HealthCare Commission (www.urac.org). URAC's accreditation program is the first of its kind, requiring compliance with 53 standards of quality and accountability, verified by independent audit. A.D.A.M. is among the first to achieve this important distinction for online health information and services. Learn more about A.D.A.M.'s editorial process . A.D.A.M. is also a founding member of Hi-Ethics (www.hiethics.com) and subscribes to the principles of the Health on the Net Foundation (www.hon.ch).

The information provided herein should not be used during any medical emergency or for the diagnosis or treatment of any medical condition. A licensed medical professional should be consulted for diagnosis and treatment of any and all medical conditions. Call 911 for all medical emergencies. Links to other sites are provided for information only -- they do not constitute endorsements of those other sites. © 1997-2007 A.D.A.M., Inc. Any duplication or distribution of the information contained herein is strictly prohibited.