Hypertension is the term used to describe high blood pressure.

Blood pressure readings are measured in millimeters of mercury (mmHg) and usually given as two numbers. For example, 120 over 80 (written as 120/80 mmHg).

• 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.

See also: Blood pressure

High blood pressure; HBP; Blood pressure - high

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
• 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. Smoking, obesity, and diabetes are all risk factors for hypertension.

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 abuse
• Anxiety and stress
• Arteriosclerosis
• Birth control pills
• 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
• Medications
  • Appetite suppressants
  • Certain cold medications
  • Corticosteroids
  • Migraine medications
• Hemolytic-uremic syndrome
• Henoch-Schonlein purpura
• Obesity
• Pain
• Periarteritis nodosa
• Pheochromocytoma
• Pregnancy (called gestational hypertension)
• Primary hyperaldosteronism
• Renal artery stenosis
• Retroperitoneal fibrosis
• Wilms' tumor

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.

Kaplan NM. Systemic Hypertension: Therapy. In: Libby P, Bonow RO, Mann DL, Zipes DP, eds. Braunwald's Heart Disease: A Textbook of Cardiovascular Medicine. 8th ed. Philadelphia, Pa: Saunders Elsevier; 2007:chap 41.

Wolff T, Miller T. Evidence for the reaffirmation of the U.S. Preventive Services Task Force recommendation on screening for high blood pressure. Ann Intern Med. 2007;147:787-791.