ATTENTION

If you or someone you know is experiencing a mental health crisis, call 988 for 24/7 free and confidential crisis support. You do not have to be suicidal to call. Access more info and resources on suicide prevention, emotional and mental health support

toggle mobile menu Menu
toggle search menu

Site Navigation

Supplemental

Menu

Blood pressure

Blood pressure

Blood pressure is the force of blood inside an artery. A blood pressure reading measures the force of blood against the walls of an artery.

Blood pressure is measured by temporarily stopping the flow of blood in an artery, using a cuff placed around the upper arm. Air is added to the cuff until blood flow stops. As the air is released, blood begins to flow through the artery again. Blood pressure is measured as the blood begins to flow again.

  • Blood pressure readings consist of an upper and lower number (such as 120 over 90 or 120/90). Blood pressure readings are measured in units called millimeters of mercury (mm Hg).
  • Systolic blood pressure is the first or upper number in a blood pressure reading. Systolic pressure is the pressure of blood against the artery walls when the heart has just finished contracting or pumping.
  • Diastolic blood pressure is the second or lower number in a blood pressure reading. Diastolic pressure is the pressure of blood against the artery walls between heartbeats, when the heart is relaxed and filling with blood.

This information does not replace the advice of a doctor. Healthwise, Incorporated disclaims any warranty or liability for your use of this information. Your use of this information means that you agree to the Terms of Use. Healthwise is a URAC accredited health web site content provider. Privacy Policy. How this information was developed to help you make better health decisions.

© 1995- Healthwise, Incorporated. Healthwise, Healthwise for every health decision, and the Healthwise logo are trademarks of Healthwise, Incorporated.