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Blood Pressure (Diastolic)
About Blood Pressure (Diastolic)
Each time your heart beats, it pumps blood into your arteries (the blood vessels that carry blood from your heart to the tissues and organs in your body). A blood pressure measurement is a test that measures the force (pressure) in your arteries as your heart pumps. Blood pressure is reported as two numbers, the systolic pressure over the diastolic pressure. For example, a blood pressure reading of 120/80 means a systolic of 120 and a diastolic of 80.
Many things can change your blood pressure, causing it to rise or fall throughout the day.
If your blood pressure is high on several different measurements on different days, you might have high blood pressure, also known as hypertension. Around half of American adults have high blood pressure. It increases the risk of life-threatening conditions, including heart attack and stroke. But high blood pressure rarely causes symptoms. A blood pressure measurement helps diagnose high blood pressure early, so it may be treated before it leads to serious complications.
Main source: MedlinePlus ↗
Useful for
A blood pressure measurement is most often used to diagnose high blood pressure.
It may also be used to test for low blood pressure if you have certain symptoms, such as dizziness, lightheadedness, nausea, cold and sweaty skin, pale skin, fainting, or weakness.
Blood pressure measurements are also used to monitor people who already have high or low blood pressure to see how well treatment is working.
Main source: MedlinePlus ↗
Interpretation
Your results, also known as a blood pressure reading, will contain two numbers. The top or first number is the systolic pressure. The bottom or second number is the diastolic pressure. Blood pressure readings are also labeled by categories, ranging from normal to crisis. Blood pressure is measured in millimeters of mercury (mm Hg).
Your blood pressure measurement can go up and down. Your provider will only usually diagnose you with high blood pressure if you have two or more high blood pressure readings on different days. They may also consider your blood pressure readings over a period of time, your medical and family history, and if you have other symptoms before diagnosing you with high blood pressure.
If your child is younger than 13, your provider will compare their blood pressure readings with what is common for children the same age, sex, and height.
For general wellness information only. Talk to a clinician about your specific results.
Main source: MedlinePlus ↗
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Sources
Last updated 2026-05-02
This page presents source-specific reference data and sourced explanations. For general wellness information only. This is not medical advice. For diagnosis or treatment of any condition, talk to a qualified clinician.