Blood pressure: low

Blood pressure is the force exerted by the circulating blood on the walls of the arteries, the veins, and the chambers of the heart. It is affected by the strength of the heart's contractions and several other factors. The pressure is higher when the heart is contracting and lower when the heart is relaxing between beats.

Low blood pressure can either be a sign of good health or a warning signal to a health problem. People with high fitness levels tend to have lower blood pressures than those who are less fit. Low blood pressure in fit people results from a well-conditioned, healthy heart.

Very low blood pressure can quickly become a problem. When blood pressure drops too low there is the danger of the body not getting enough oxygen carrying blood. Normal body functions like breathing, movement, and brain function can be impaired and damage can occur. Rapid drops in blood pressure that threaten life can occur due to loss of blood, severe infections, or low body temperature due to cold exposure. Emergency treatment for these conditions raises blood pressure to a more normal level.

There is a temporary form of low blood pressure that causes light-headedness when standing up suddenly from sitting or lying. Dizziness or fainting may result. If symptoms persist, seek medical evaluation.

To avoid such symptoms try these tips:

• sit for a moment before standing and stand a moment before walking

• stand up slowly from lying down or sitting

• walk in place briefly while pulling in your stomach muscles several times (This aids the return of blood flow from the legs.)

• avoid prolonged periods in the sun

• avoid fasting

Low blood pressure can also result from the following:

• medication taken for high blood pressure

• pregnancy

• diabetes or

• low thyroid or low adrenal gland function

Regular exams by your healthcare provider may detect low blood pressure as a warning signal to a health problem.

Last Reviewed: 2005

Disclaimer: This content is reviewed periodically and is subject to change as new health information becomes available. The information provided is intended to be informative and educational and is not a replacement for professional medical evaluation, advice, diagnosis or treatment by a healthcare professional.

HIL File CARD3002.RF2 VRS# 6146 Data Version 7.0 Copyright 1999, 2002 McKesson Health Solutions LLC. All rights reserved.