Prehypertension

Topic Overview

What is prehypertension?

Prehypertension is blood pressure that is higher than normal but not high enough to be high blood pressure. It is a warning that your blood pressure is going up.

Blood pressure is a measure of how hard your blood pushes against the walls of your arteries. Blood pressure that is too high (also called hypertension) harms your blood vessels. This raises your risk of heart attack, stroke, kidney failure, and other health problems.

Blood pressure is shown as two numbers, such as 120/80 (say "120 over 80"). The top number is the pressure when the heart pumps blood. It is called the systolic pressure. The bottom number is the pressure when the heart relaxes and fills with blood. It is called the diastolic pressure. An ideal blood pressure for an adult is less than 120/80. High blood pressure is 140/90 or higher. Prehypertension is between ideal blood pressure and hypertension. You have prehypertension if your top number is 120 to 139, or your bottom number is 80 to 89, or both.

What makes blood pressure go up?

Experts don't know the exact cause of high blood pressure. But they agree that some things can make blood pressure go up. They include not getting enough exercise and being overweight. Eating foods that have too much sodium (salt) and drinking too much alcohol also can raise blood pressure.

What are the symptoms?

Blood pressure that is higher than normal does not cause symptoms. Most people feel fine. They find out they have higher-than-normal blood pressure during a routine exam or a doctor visit for another problem.

How is prehypertension diagnosed?

A simple test with a blood pressure cuff is all you need to find out your blood pressure. The doctor or nurse puts the cuff around your arm and pumps air into the cuff. The cuff squeezes your arm. The doctor or nurse takes your blood pressure while letting the air out of the cuff.

After measuring your blood pressure, your doctor may ask you to test it again when you are home.^{footnote 1} This is because your blood pressure can change throughout the day. And sometimes blood pressure is high only because you are seeing a doctor. This is called white-coat hypertension. To diagnose high blood pressure, your doctor needs to know if your blood pressure is high throughout the day.

So your doctor may ask you to monitor your blood pressure at home to make sure that it actually is high. You may get an ambulatory blood pressure monitor or a home blood pressure monitor. These devices measure your blood pressure several times throughout the day.

How is it treated?

Heart-healthy lifestyle changes can lower your blood pressure if you have prehypertension.

To lower blood pressure:

• Do not smoke or use other tobacco products. If you do smoke, talk to your doctor about treatments that can help you quit.
• Stay at a healthy weight. Lose weight if you are overweight. Losing as little as 10 lb (4.5 kg) can help lower your blood pressure.
• Be active on most days of the week. Try to do moderate activity at least 2½ hours a week. Or try to do vigorous activity at least 1¼ hours a week.
• Eat a healthy diet. The DASH diet is an eating plan that can help lower your blood pressure. DASH stands for Dietary Approaches to Stop Hypertension. It focuses on eating foods that are high in calcium, potassium, and magnesium. The DASH diet includes lots of fruits and vegetables, as well as whole grains, fish, and poultry. Your doctor may suggest that you talk to a dietitian if you need help planning what to eat.
• Limit sodium. For good health, less is best. Most people shouldn't eat more than 2,300 milligrams (mg) of sodium a day. If you limit your sodium to 1,500 mg a day, you can lower your blood pressure even more.^{footnote 2} Your doctor will tell you how much you can have. Do not add salt to your food. Limit processed and canned foods, such as soups, frozen meals, and packaged snacks.
• Limit alcohol to 1 drink a day for women and no more than 2 drinks a day for men. If your blood pressure tends to go up when you have alcohol, your doctor may suggest that you do not drink any alcohol.