Hypertension: A Patient Handout

High blood pressure increases your chance (or risk) for getting heart disease and/or kidney disease, and for having a stroke. It is especially dangerous because it often has no warning signs or symptoms. Regardless of race, age, or gender, anyone can develop high blood pressure. It is estimated that one in every four American adults has high blood pressure. Once high blood pressure develops, it usually lasts a lifetime. You can prevent and control high blood pressure by taking action.

Why Is High Blood Pressure Important?

High blood pressure is dangerous because it makes the heart work too hard. It also makes the walls of the arteries hard. High blood pressure increases the risk for heart disease and stroke, the first- and third-leading causes of death for Americans. High blood pressure can also cause other problems, such as heart failure, kidney disease, and blindness.

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. 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% 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 Detection

You can find out if you have high blood pressure by having your blood pressure checked regularly. Most doctors will diagnose a person with high blood pressure on the basis of two or more readings, taken on several occasions. A consistent blood pressure reading of 140/90 mmHg or higher is considered hypertension, another term for high blood pressure.

Some people experience high blood pressure only when they visit the doctor's office ("white-coat hypertension"). If your doctor suspects this, you may be asked to monitor your blood pressure at home or asked to wear a device called an ambulatory blood pressure monitor. This device is usually worn for 24 hours and can take blood pressure every 30 minutes.

Tips for Having Your Blood Pressure Taken

  • Don't drink coffee or smoke cigarettes 30 minutes before having your blood pressure measured.
  • Before the test, sit for five minutes with your back supported and your feet flat on the ground. Rest your arm on a table at the level of your heart.
  • Wear short sleeves so your arm is exposed.
  • Go to the bathroom prior to the reading. A full bladder can change your blood pressure reading.
  • Get two readings, taken at least two minutes apart, and average the results.
  • Ask the doctor or nurse to tell you the blood pressure reading in numbers.

Prevention

You can take steps to prevent high blood pressure by adopting a healthy lifestyle. These steps include maintaining a healthy weight; being physically active; following a healthy eating plan that emphasizes fruits, vegetables, and low-fat dairy foods; choosing and preparing foods with less salt and sodium; and, if you drink alcoholic beverages, drinking in moderation.

Healthy Eating. Research has shown that following a healthy eating plan can both reduce the risk of developing high blood pressure and lower an already elevated blood pressure.

For an overall eating plan, consider the DASH eating plan. DASH stands for Dietary Approaches to Stop Hypertension, a clinical study that tested the effects of nutrients in food on blood pressure. Study results indicated that elevated blood pressures were reduced by an eating plan that emphasizes fruits, vegetables, and low-fat dairy foods, and is low in saturated fat, total fat, and cholesterol. The DASH eating plan includes whole grains, poultry, fish, and nuts and has reduced amounts of fats, red meats, sweets, and sugared beverages.

A second clinical study, called DASH-Sodium looked at the effect of a reduced dietary sodium intake on blood pressure as people followed either the DASH eating plan or a typical American diet. Results showed that reducing dietary sodium lowered blood pressure for both the DASH eating plan and the typical American diet. The biggest blood pressure-lowering benefits were for those eating the DASH eating plan at the lowest sodium level (1,500 mg per day).

Reduce Salt and Sodium in Your Diet. A key to healthy eating is choosing foods lower in salt and sodium. Most Americans consume more salt than they need. The current recommendation is to consume less than
2.4 g (2,400 mg) of sodium a day. That equals 6 g (about 1 teaspoon) of table salt a day. The 6 g include all salt and sodium consumed, including that used in cooking and at the table. For someone with high blood pressure, the doctor may advise eating less salt and sodium, as recent research has shown that people consuming diets of 1,500 mg of sodium had even better blood pressure lowering benefits. These lower-sodium diets also can keep blood pressure from rising and help blood pressure medicines work better.

Issues for Women

Three out of four women with high blood pressure know they have it. Yet fewer than one in three are controlling their blood pressure. All women should take steps to control their blood pressure.

Pregnancy. Although many pregnant women with high blood pressure have healthy babies without serious problems, high blood pressure can be dangerous for both the mother and the fetus. Women with pre-existing or chronic high blood pressure are more likely to have certain complications during pregnancy than those with normal blood pressure. However, some women develop high blood pressure while they are pregnant (often called gestational hypertension).

The effects of high blood pressure range from mild to severe. High blood pressure can harm the mother's kidneys and other organs, and it can cause low birth weight and early delivery. In the most serious cases, the mother develops preeclampsia, which can threaten the lives of both the mother and the fetus.

Oral Contraceptives. Women taking oral contraceptives experience a small but detectable increase in both systolic and diastolic blood pressure, usually in the normal range. Women age 35 and older who smoke cigarettes are at even greater risk for heart disease and stroke and are encouraged to quit smoking. If they are unable to quit smoking, they should talk to their doctor about using other forms of contraception.

Hormone Replacement Therapy. A recent study indicated that blood pressure does not increase significantly with hormone replacement therapy in most women with and without high blood pressure. However, a few women may experience a rise in blood pressure attributable to estrogen therapy. Therefore, it is recommended that all women treated with hormone replacement therapy have their blood pressure monitored more frequently after such therapy is started.

Source: National Heart, Lung and Blood Institute. Available at: www.nhlbi.nih.gov/hbp/index.html. Accessed Aug. 16, 2007.