What is high blood pressure?

Blood pressure is a measure of how hard the blood pushes against the walls of your arteries. It's normal for blood pressure to go up and down throughout the day. But if it stays up, you have high blood pressure (hypertension).

Two numbers tell you your blood pressure. The first (top) number is the systolic pressure. It shows how hard the blood pushes when your heart is pumping. The second (bottom) number is the diastolic pressure. It shows how hard the blood pushes between heartbeats, when your heart is relaxed and filling with blood.

High blood pressure means that the top number stays high, or the bottom number stays high, or both. For diagnosis, the top number may be 130 to 140 or higher. The bottom number may be 80 to 90 or higher.

High blood pressure increases the risk of stroke, heart attack, and other problems.

High blood pressure doesn't usually cause symptoms. Most people don't know they have it until they go to the doctor for some other reason. Very high blood pressure (such as 180/120 or higher) can cause severe headaches and vision problems.

Your care provider uses a blood pressure monitor to screen for high blood pressure. A blood pressure cuff is wrapped around your bare upper arm. The cuff is then pumped up. The cuff is slowly deflated, and the monitor shows your blood pressure numbers. Either an automatic or manual monitor can be used.

After measuring your blood pressure, your doctor may ask you to test it again when you are home. This is because your blood pressure can change throughout the day. And sometimes blood pressure is high only because you are seeing the doctor. This is called white-coat hypertension.

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.

• Your doctor will suggest making lifestyle changes to help your heart. For example, your doctor may ask you to eat healthy foods, quit smoking, lose extra weight, and be more active.
• If lifestyle changes don’t help enough, your doctor may recommend that you take medicine.
• When blood pressure is very high, medicines are needed to lower it.

Making lifestyle changes can help control high blood pressure. Try to:

Stay at a healthy weight.

If you're overweight, losing as little as 10 lb (5 kg) may lower your blood pressure.

Cut back on sodium.

Try to limit how much sodium you eat to less than 2,300 milligrams (mg) a day. Your doctor may ask you to try to eat less than 1,500 mg a day.

Get active.

Try to do moderate activity at least 2½ hours a week. Or do vigorous activity at least 1¼ hours a week.

Drink less alcohol.

Alcohol can raise blood pressure. Drink it in moderation, if at all.

Check your blood pressure at home.

Seeing small improvements can help you keep going with your lifestyle changes.

If you smoke, try to quit. Smoking increases your risk for heart attack and stroke. If you need help quitting, talk to your doctor about stop-smoking programs and medicines.