Do you often wonder what your blood pressure numbers mean? Doctors call them systolic (the top number) and diastolic (the bottom number) blood pressure.
Knowing both is important and could save your life.
What Does the Systolic Blood Pressure Number Mean?
When your heart beats, it squeezes and pushes blood through your arteries to the rest of your body. This force creates pressure on those blood vessels, and that's your systolic blood pressure.
A normal systolic pressure is below 120.
A reading of 140 or more is high blood pressure (also called hypertension).
What Does the Diastolic Blood Pressure Number Mean?
The diastolic reading, or the bottom number, is the pressure in the arteries when the heart rests between beats. This is the time when the heart fills with blood and gets oxygen.
A normal diastolic blood pressure is lower than 80.
90 or higher is high blood pressure.
Our charts below have more details.
How Your Numbers Translate
How Is Blood Pressure Measured?
A doctor or nurse will measure your blood pressure with a small gauge attached to an inflatable cuff. It’s simple and painless.
The person taking your blood pressure wraps the cuff around your upper arm. Some cuffs go around the forearm or wrist, but often they're not as accurate.
Your doctor or nurse will use a stethoscope to listen to the blood moving through your artery.
She’ll inflate the cuff to a pressure higher than your systolic blood pressure, and it will tighten around your arm. Then she'll release it. As the cuff deflates, the first sound she hears through the stethoscope is the systolic blood pressure. It sounds like a whooshing noise. The point where this noise goes away marks the diastolic blood pressure.
In a blood pressure reading, the systolic number always comes first, and then the diastolic number. For example, your numbers may be "120 over 80" or written as 120/80.
How Often Should I Get My Blood Pressure Checked?
- If your blood pressure is normal (less than 120/80), get it checked at least every 2 years or more frequently as your doctor suggests.
- If your blood pressure is borderline high (called prehypertension) -- systolic blood pressure between 120 and 139 or diastolic blood pressure of 80 to 89 -- check it at least every year or more often as your doctor suggests. Depending on whether you have other medical issues, a “borderline” reading might be considered too high.
- If your reading is 140/90 or higher, you have high blood pressure and need to see your doctor. You may need to start medication.