High Blood Pressure
"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.
About 1 in 3 adults in the United States has high blood pressure.. High blood pressure, 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 and diastolic 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 on the next page 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.