The basics of hypertension

Provided by the NATIONAL INSTITUTES
OF HEALTH

What are high blood pressure and prehypertension?

Blood pressure is the force of blood against the walls of arteries. Blood pressure rises and falls during the day. When blood pressure stays elevated over time, it is called high blood pressure.

The medical term for high blood pressure is hypertension. High blood pressure is dangerous because it makes the heart work too hard and contributes to atherosclerosis (hardening of the arteries).

It increases the risk of heart disease and stroke, which are the first- and third-leading causes of death among Americans. High blood pressure also can result in other conditions, such as congestive heart failure, kidney disease, and blindness.

A blood pressure level of 140/90 mmHg or higher is considered high. About two-thirds of people over age 65 have high blood pressure. If your blood pressure is between 120/80 mmHg and 139/89 mmHg, then you have prehypertension. This means that you don't have high blood pressure now but are likely to develop it in the future. You can take steps to prevent high blood pressure by adopting a healthy lifestyle.

Those who do not have high blood pressure at age 55 face a 90 percent chance of developing it during their lifetimes. So high blood pressure is a condition that most people have at some point in their lives.

Both numbers in a blood pressure test are important, but for people who are 50 or older, systolic pressure gives the most accurate diagnosis of high blood pressure. Systolic pressure is the top number in a blood pressure reading. It is high if it is 140 mmHg or above.

What are the risk factors?

High blood pressure is a risk factor for heart disease and stroke.

There are other risk factors for heart disease and stroke. Most can be modified, though some cannot. The more risk factors you have, the greater your chances of developing disease. So it is important to take steps to prevent or control these risk factors.

Heart disease and stroke risk factors that can be controlled are:

•High blood pressure (hypertension).

•Abnormal cholesterol.

•Tobacco use.

•Diabetes.

•Overweight.

•Physical inactivity.

Risk factors beyond your control are:

•Age (55 years and older for men and 65 years or older for women).

•Family history of early heart disease (having a mother or sister who has been diagnosed with heart disease before age 65, or a father or brother diagnosed before age 55) or family history of stroke.

What causes high blood pressure?

The causes of high blood pressure vary. Causes may include narrowing of the arteries, a greater than normal volume of blood, or the heart beating faster or more forcefully than it should. Any of these conditions will cause increased pressure against the artery walls.

High blood pressure might also be caused by another medical problem. Most of the time, the cause is not known. Although high blood pressure usually cannot be cured, in most cases it can be prevented and controlled.

Who can develop high blood pressure?

High blood pressure is common. About 65 million American adults -- nearly 1 in 3 -- have high blood pressure. It is very common in African Americans, who may get it earlier in life and more often than whites. Many Americans tend to develop high blood pressure as they get older, but this is not a part of healthy aging.

Middle-aged Americans face a 90 percent chance of developing high blood pressure during their lives. Others at risk for developing high blood pressure are the overweight, those with a family history of high blood pressure, and those with prehypertension (120–139/80–89 mmHg).

High blood pressure occurs more often among African Americans than whites. It begins at an earlier age and is usually more severe. Further, African Americans have a higher death rate from stroke and kidney disease than whites. The good news is, treatment can control high blood pressure. In addition, lifestyle changes can prevent and control high blood pressure.

These include losing weight if overweight (losing 10 pounds can help), increasing physical activity (walking 30 minutes per day can help), following a healthy eating plan, that emphasizes fruits, vegetables, and lowfat dairy foods, choosing and preparing foods with less salt and sodium, and if you drink alcoholic beverages, drinking in moderation.

If lifestyle changes alone are not effective in keeping your blood pressure controlled, there are many blood pressure medications to help you.