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. But you can take steps to get your blood pressure back to normal.

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. The bottom number is the pressure when the heart relaxes and fills with blood. Normal blood pressure is less than 120/80. High blood pressure is 140/90 or higher. Prehypertension is between 120/80 and 140/90. Your blood pressure can be too high even if only one of the two numbers is high.

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.

Your blood pressure may be measured at two or more separate times to make sure that it is higher than normal. This is because blood pressure goes up and down throughout the day. Also, some people have higher blood pressure when they are in a doctor's office but they have normal blood pressure at other times. This is called white-coat hypertension. If you think you may have this, talk to your doctor about checking your blood pressure more often to see if you really have high blood pressure.

How is it treated?

Many people can lower their blood pressure with diet, exercise, and other lifestyle changes. If those steps don't lower your blood pressure enough, you can take medicine. But because you are treating your blood pressure before it gets too high, lifestyle changes may be all you need.

Here's what you can do to help get your blood pressure back to normal.

• Do not smoke or use other tobacco products. If you do smoke, talk to your doctor about treatments that can help you quit.
• Lose weight if you are overweight. Losing as little as 10 lb (4.5 kg) can help lower your blood pressure.
• 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.
• Cut back on salt. Some doctors recommend that you have no more than 2,300 mg (milligrams) of sodium each day. 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.
• Try to do moderate activity at least 2½ hours a week. Or try to do vigorous activity at least 1¼ hours a week. It's fine to be active in blocks of 10 minutes or more throughout your day and week.