High blood pressure (HBP) is a serious condition that can lead to coronary heart disease, heart failure, stroke, kidney failure, and other health problems.

“Blood pressure” is the force of blood pushing against the walls of the arteries as the heart pumps out blood. If this pressure rises and stays high over time, it can damage the body in many ways.

Overview

About 1 in 3 adults in the United States has HBP. HBP itself usually has no symptoms. You can have it for years without knowing it. During this time, though, it can damage the heart, blood vessels, kidneys, and other parts of your body. This is why knowing your blood pressure numbers is important, even when you’re feeling fine. If your blood pressure is normal, you can work with your health care team to keep it that way. If your blood pressure is too high, you need treatment to prevent damage to your body’s organs.

Blood Pressure Numbers

Blood pressure numbers include systolic (sis-TOL-ik) and diastolic (di-a-STOL-ik) pressures. Systolic blood pressure is the pressure when the heart beats while pumping blood. Diastolic blood pressure is the pressure when the heart is at rest between beats. You will most often see blood pressure numbers written with the systolic number above or before the diastolic, such as 120/80 mmHg. (The mmHg is millimeters of mercury—the units used to measure blood pressure.) The table below shows normal numbers for adults. It also shows which numbers put you at greater risk for health problems. Blood pressure tends to goes up and down, even in people who have normal blood pressure. If your numbers stay above normal most of the time, you’re at risk.

Categories for Blood Pressure Levels in Adults (in mmHg, or millimeters of mercury)

Category

Normal Prehypertension
Systolic (top number) Less than 120 120-139
Diastolic (bottom number) Less than 80 80-89

High blood pressure

Stage 1 Stage 2
Systolic (top number) 140–159 160 or higher
Diastolic (bottom number) 90–99 100 or higher

The ranges in the table apply to most adults (aged 18 and older) who don’t have short-term serious illnesses. All levels above 120/80 mmHg raise your risk, and the risk grows as blood pressure levels rise. “Prehypertension” means you’re likely to end up with HBP, unless you take steps to prevent it. If you’re being treated for HBP and have repeat readings in the normal range, your blood pressure is under control. However, you still have the condition. You should see your doctor and stay on treatment to keep you blood pressure under control.

Your systolic and diastolic numbers may not be in the same blood pressure category. In this case, the more severe category is the one you’re in. For example, if your systolic number is 160 and your diastolic number is 80, you have stage 2 HBP. If your systolic number is 120 and your diastolic number is 95, you have stage 1 HBP.

If you have diabetes or chronic kidney disease, HBP is defined as 130/80 mmHg or higher. HBP numbers also differ for children and teens. (For more information, see “How Is High Blood Pressure Diagnosed?“)

Outlook

Blood pressure tends to rise with age. Following a healthy lifestyle helps some people delay or prevent this rise in blood pressure. People who have HBP can take steps to control it and reduce their risks for related health problems. Key steps include following a healthy lifestyle, having ongoing medical care, and following the treatment plan that your doctor prescribes.

November 2008