Conditions InDepth: Hypertension
Hypertension
is the medical term for high blood pressure. Blood pressure is the force of blood flow against the artery walls.
Blood pressure measurements are read as two numbers. The higher number, called the systolic pressure, represents the pressure in the artery when the heart beats. The lower number, called the diastolic pressure, represents the pressure when the heart is at rest. Normal blood pressure is in the range of 120/80. High blood pressure, or hypertension, is defined as systolic pressure greater than 140 and/or diastolic pressure greater than 90.
Blood pressure fluctuates throughout each day.
In most cases, the cause of hypertension is unknown. Genetic factors may be involved. In addition, the following conditions may cause hypertension: narrowing of the arteries, excess fluid in the blood, stronger than normal heartbeats, certain medications, or disorders of the kidneys, nervous system, or endocrine system (hormones).
Over time, high blood pressure can damage organs and tissues. It also increases the risk of coronary heart disease,
stroke
, and
congestive heart failure
, and death.
According to the American Heart Association, about 73 million Americans have high blood pressure, but it's estimated that over half of these people do not have their condition under control.
What are the risk factors for hypertension?What are the symptoms of hypertension?How is hypertension diagnosed?What are the treatments for hypertension?Are there screening tests for hypertension?How can I reduce my risk of hypertension?What questions should I ask my doctor?What is it like to live with hypertension?Where can I get more information about hypertension?References
High blood pressure.
American Heart Association
website. Available at:
http://www.americanheart.org/
.
Accessed June 18, 2009.
High blood pressure. National Heart, Lung, and Blood Institute
website. Available at:
http://www.nhlbi.nih.gov/health/dci/Diseases/Hbp/HBP%5FWhatIs.html
.
Updated November 2008. Accessed June 18, 2009.
High blood pressure statistics. American Heart Association
website. Available at:
http://www.americanheart.org/presenter.jhtml?identifier=4621
.
Accessed June 18, 2009.
12/11/2009
DynaMed's Systematic Literature Surveillance
http://www.ebscohost.com/dynamed/what.php
: He J, Gu D, Chen J, et al. Premature deaths attributable to blood pressure in China: a prospective cohort study.
Lancet
.
2009;374(9703):1765-72.