Alternative Names diastolic BP, diastolic blood pressure, systolic blood pressure, systolic BP, BP
Definition This test measures the force that blood exerts against the walls of the arteries as the heart pumps blood through the arteries.
High blood pressure can increase the risk of kidney failure, heart failure, stroke, which is a blood clot in the brain, and heart attack. It is important for everyone to know what his or her blood pressure is, so that changes can be made if it is not within a healthy range.
How is the test performed? A person is seated with his or her bare arm resting on a table. The arm is bent at the elbow so that it sits at the same level as the heart. A blood pressure cuff is placed on the upper arm and inflated. A technician wearing a stethoscope listens carefully as air is slowly let out of the cuff. He or she notes the systolic and diastolic pressures. Systolic pressure is the blood pressure at the time the heart is contracted. Diastolic pressure is the blood pressure at the time the heart is relaxed.
What is involved in preparation for the test? A person should request specific instructions from his or her doctor or nurse.
What do the test results mean? The ideal systolic pressure is around 120 millimetres of mercury (mm Hg). The ideal diastolic pressure is 70 to 80 mm Hg. These values are usually expressed as a ratio such as 120/70.
Blood pressure lower than normal is called hypotension.
Blood pressure higher than normal is called hypertension. In cases of mild hypertension, the diastolic pressure is consistently 90 to 99 mm Hg. In cases of severe hypertension, the systolic pressure is 180 - 209 mm Hg, and the diastolic pressure is above 110 - 119 mm Hg.
Blood pressure readings may be affected by:
heart disorders.
conditions that affect the nervous system.
kidney disorders.
pregnancy-induced hypertension, or a condition marked by very high blood pressure in pregnant women.
emotions like fear, anger or stress.
certain medications.
Author: Reviewer: eknowhow Medical Review Panel Editor: Dr John Hearne Last Updated: 17/11/2004 Contributors Potential conflict of interest information for reviewers available on request
