ADAM Health Encyclopedia

High blood pressure

Definition

Hypertension is blood pressure that is often higher than 140/90 millimeters of mercury (mm Hg).

Alternative Names

Considerations

Blood pressure can vary throughout the day and change with activity. A blood pressure measurement has two numbers:

• The top (systolic) number is the blood pressure during the heartbeat.
• The bottom (diastolic) number is the blood pressure between beats.

According to the American Heart Association, adults should normally have a blood pressure less than 120/80 mm Hg.

Pre-hypertension is when the top number is 120-139 mm Hg and the bottom number is over 80-89 mm Hg on most measurements. If you have pre-hypertension, you are likely to develop high blood pressure at some time in your life, unless you make lifestyle changes.

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.

Causes

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.

Some reasons for secondary hypertension include:

• Anxiety and stress
• Appetite suppressants
• Arteriosclerosis
• Birth control pills
• Certain medicines used to treat colds
• Coarctation of the aorta
• Cocaine use
• Diabetes
• Kidney disease
• Migraine medicines
• Obesity
• Pain
• Pregnancy (called gestational hypertension)
• Regularly drinking too much alcohol and alcohol toxicity
• Renal artery stenosis
• Too much salt in your diet

Home Care

Ask your doctor how often you should have your blood pressure checked. Some people may need to check their blood pressure regularly at home.

Medicines and lifestyle changes, such as exercising and following a health diet, may be needed. If you have other risk factors for heart disease, especially diabetes, your doctor will consider starting medications sooner rather than later. The goal is to lower your blood pressure below 140/90, or below 130/80 if you have diabetes or kidney disease.

When to Contact a Medical Professional

If you have high blood pressure, you will have regularly scheduled appointments with your doctor.

Call your health care provider right away if home monitoring shows that your blood pressure remains high or you have any of the following symptoms:

• Chest pain
• Confusion
• Excessive tiredness
• Nausea and vomiting
• Severe headache
• Shortness of breath
• Significant sweating
• Vision changes

Your health care provider will perform a physical exam and check your blood pressure. If you monitor your blood pressure at home, you may be asked the following questions:

• Has your blood pressure increased recently?
• Did it suddenly become high?
• How much has the blood pressure gone up within the past two weeks?
• What was your most recent blood pressure reading?
• What was the previous blood pressure reading?
• What is the average systolic (top number) and diastolic (bottom number)?
• What other symptoms do you have?

• Chem-20
• Echocardiogram
• Urinalysis
• X-ray of the kidneys

Prevention

People with high blood pressure may be told to reduce how much salt they eat.

Other lifestyle changes include exercising, quitting smoking, losing weight, and avoiding drinking too much alcohol.

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.

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.

Zipes DP, Libby P, Bonow RO, Braunwald E, eds. Braunwald's Heart Disease: A Textbook of Cardiovascular Medicine, 7th ed. St. Louis, Mo; WB Saunders; 2005:959-1007.