| Share
 

Blood Pressure Explained

Blood pressure is the force of blood against the walls of arteries. Blood pressure is recorded as two numbers—the systolic pressure (as the heart beats) over the diastolic pressure (as the heart relaxes between beats). The measurement is written one above or before the other, with the systolic number on top and the diastolic number on the bottom. For example, a blood pressure measurement of 120/80 mm Hg (millimeters of mercury) is expressed verbally as “120 over 80.”

Normal blood pressure is less than 120 mm Hg systolic and less than 80 mm Hg diastolic.

When systolic and diastolic blood pressures fall into different categories, the higher category should be used to classify blood pressure level. For example, 160/80 mm Hg would be stage 2 hypertension (high blood pressure).

 Blood pressure level (mm Hg)
CategorySystolicDiastolic
Normal< 120< 80
Prehypertension120–13980–89
High blood pressure
 Stage 1 hypertension140–15990–99
 Stage 2 hypertension>=160>=100
NOTE: < means less than; >= means greater than or equal to.
Source: National Heart, Lung, and Blood Institute.

Information Please® Database, © 2007 Pearson Education, Inc. All rights reserved.

America’s Best Hospitals, 2006HealthBlood Types

More on Blood Pressure Explained from Infoplease:

  • Health & Nutrition - Personal Health, Nutrition, Disease and Mortality, Drugs and Alcohol

Premium Partner Content
HighBeam Research
Documents Images and Maps Reference
(from Newspapers, Magazines, Journals, Newswires, Transcripts and Books)

Research our extensive archive of more than 80 million articles from 6,500 publications.

Additional search results provided by HighBeam Research, LLC. © Copyright 2005. All rights reserved.

24 X 7

Private Tutor

Click Here for Details
24 x 7 Tutor Availability
Unlimited Online Tutoring
1-on-1 Tutoring