What is systolic blood pressure?

When your physician takes your blood pressure, you will be told two numbers: the first number is your systolic blood pressure. This number tells you how much force your blood is exerting against artery walls when it is pumping through your body. Arteries are large blood vessels that deliver blood from your heart to the rest of your body. The systolic blood pressure is specifically the measurement of this force during a heartbeat - when your heart is pumping blood to the body. (The other number, your diastolic pressure, is the reading between heartbeats.) A systolic reading higher than 120 mmHg is above normal and may be an indicator that you need treatment for high blood pressure, or hypertension. Watching your weight and avoiding salt can help lower blood pressure if your numbers are not too high.

Blood pressure numbers include systolic pressure and diastolic pressure. 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.

For years it was thought that systolic blood pressure was less important than diastolic hypertension. The upper number was thought to matter less than the lower number. In fact, doctors were hesitant to treat blood pressure in many of these cases.

Now researchers have shown that systolic hypertension is at least as important as diastolic hypertension as a cause of future heart attacks, strokes, and other problems. In fact, many older adults have systolic hypertension, which can cause just as much harm as high blood pressure when both numbers are elevated. In fact, if your systolic blood pressure (top number) is 140 higher, you may be more likely to develop kidney disease and cardiovascular disease even if the diastolic number (lower number) is not too high.

So, if the systolic blood pressure is consistently high, many physicians would favor treatment to lower the blood pressure number to normal. In fact, the blood pressure can be controlled effectively and safely in most cases.

Cardiovascular specialist Dr. Merle Myerson explains the definition of systolic blood pressure. Watch Dr. Myerson's video for important tips and information about heart health.

Systolic pressure is the pressure of blood against the artery walls when the heart has just finished contracting or pumping out blood. (Diastolic pressure is the pressure of blood against the artery walls between heartbeats, when the heart is relaxed and filling with blood.)

Systolic blood pressure is the upper number of a blood pressure reading. For example, if a person's systolic pressure is 120 millimeters of mercury (mm Hg) and the diastolic pressure is 80 mm Hg, blood pressure is recorded as 120/80 and read as "120 over 80."