High blood pressure (Hypertension)

Definition

Hypertension is the term doctors use for high blood pressure.

Blood pressure readings are measured in millimeters of mercury (mmHg) and usually given as 2 numbers. For example, 140 over 90 (written as 140/90).

• The top number is your systolic pressure, the pressure created when your heart beats. It is considered high if it is consistently over 140.
• The bottom number is your diastolic pressure, the pressure inside blood vessels when the heart is at rest. It is considered high if it is consistently over 90.

Either or both of these numbers may be too high.

Pre-hypertension is when your systolic blood pressure is between 120 and 139 or your diastolic blood pressure is between 80 and 89 on multiple readings. If you have pre-hypertension, you are more likely to develop high blood pressure at some point.

See also: Blood pressure

Alternative Names

Causes

Blood pressure measurements are the result of the force of the blood produced by the heart and the size and condition of the arteries.

Many factors can affect blood pressure, including how much water and salt you have in your body, the condition of your kidneys, nervous system, or blood vessels, and the levels of different body hormones.

High blood pressure can affect all types of people. You have a higher risk of high blood pressure if you have a family history of the disease. High blood pressure is more common in African Americans than Caucasians.

Most of the time, no cause is identified. This is called essential hypertension. High blood pressure that results from a specific condition, habit, or medication is called secondary hypertension.

Too much salt in your diet can lead to high blood pressure. Secondary hypertension may also be due to:

• Adrenal gland tumor
• Alcohol poisoning
• Anxiety and stress
• Appetite suppressants
• Arteriosclerosis
• Birth control pills
• Certain cold medicines
• Coarctation of the aorta
• Cocaine use
• Cushing syndrome
• Diabetes
• Kidney disease, including:
  • Glomerulonephritis (inflammation of kidneys)
  • Kidney failure
  • Renal artery stenosis
  • Renal vascular obstruction or narrowing
• Migraine medicines
• Hemolytic-uremic syndrome
• Henoch-Schonlein purpura
• Obesity
• Pain
• Periarteritis nodosa
• Pregnancy (called gestational hypertension)
• Radiation enteritis
• Renal artery stenosis
• Retroperitoneal fibrosis
• Wilms' tumor

References

Seventh Report of the Joint National Committee on Prevention, Detection, Evaluation, and Treatment of High Blood Pressure (JNC 7). Rockville, Md. National Heart, Lung, and Blood Institute, US Department of Health and Human Services; August 2004. National Institutes of Health Publication No. 04-5230.

Wang Y, Wang QJ. The prevalence of prehypertension and hypertension among US adults according to the new joint national committee guidelines: new challenges of the old problem. Arch Intern Med. 2004;164(19):2126-34.

Eyre H, Kahn R, Robertson RM, et al. Preventing cancer, cardiovascular disease, and diabetes: A common agenda for the American Cancer Society, the American Diabetes Association, and the American Heart Association. Circulation. 2004;109(25):3244-55.

Berg AO. Screening for High Blood Pressure Recommendations and Rationale U.S. Preventive Services Task Force. USPSTF Guide to Clin Preventive Services. June 1, 2003; 1.

Whelton PK, He J, Appel LJ, et al. Primary prevention of hypertension: Clinical and public health advisory from The National High Blood Pressure Education Program. JAMA. 2002;288(15):1882-8.