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

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

Most of the time, there are no symptoms. Symptoms that may occur include:

• Chest pain
• Confusion
• Ear noise or buzzing
• Irregular heartbeat
• Nosebleed
• Tiredness
• Vision changes

If you have a severe headache or any of the symptoms above, see your doctor right away. These may be signs of a complication or dangerously high blood pressure called malignant hypertension.

Your health care provider will perform a physical exam and check your blood pressure. If the measurement is high, your doctor may think you have high blood pressure. The measurements need to be repeated over time, so that the diagnosis can be confirmed.

If you monitor your blood pressure at home, you may be asked the following questions:

• 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) reading?
• Has your blood pressure increased recently?

Other tests may be done to look for blood in the urine or heart failure. Your doctor will look for signs of complications to your heart, kidneys, eyes, and other organs in your body.

These tests may include:

• Chem-20
• Echocardiogram
• Urinalysis
• Ultrasound of the kidneys

The goal of treatment is to reduce blood pressure so that you have a lower risk of complications.

There are many different medicines that can be used to treat high blood pressure, including:

• Alpha blockers
• Angiotensin-converting enzyme (ACE) inhibitors
• Angiotensin receptor blockers (ARBs)
• Beta-blockers
• Calcium channel blockers
• Central alpha agonists
• Diuretics
• Renin inhibitors, including aliskiren (Tekturna)
• Vasodilators

Your doctor may also tell you to exercise, lose weight, and follow a healthier diet. If you have pre-hypertension, your doctor will recommend the same lifestyle changes to bring your blood pressure down to a normal range.

Often, a single blood pressure drug may not be enough to control your blood pressure, and you may need to take two or more drugs. It is very important that you take the medications prescribed to you. If you have side effects, your health care provider can substitute a different medication.

Most of the time, high blood pressure can be controlled with medicine and lifestyle changes.

• Aortic dissection
• Blood vessel damage (arteriosclerosis)
• Brain damage
• Congestive heart failure
• Kidney damage
• Kidney failure
• Heart attack
• Hypertensive heart disease
• Stroke
• Vision loss

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

Even if you have not been diagnosed with high blood pressure, it is important to have your blood pressure checked during your yearly check-up, especially if someone in your family has or had high blood pressure.

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

Adults over 18 should have their blood pressure checked routinely.

Lifestyle changes may help control your blood pressure:

• Lose weight if you are overweight. Excess weight adds to strain on the heart. In some cases, weight loss may be the only treatment needed.
• Exercise regularly. If possible, exercise for 30 minutes on most days.
• Eat a diet rich in fruits, vegetables, and low-fat dairy products while reducing total and saturated fat intake (the DASH diet is one way of achieving this kind of dietary plan). (See: Heart disease and diet)
• Avoid smoking. (See: Nicotine withdrawal)
• If you have diabetes, keep your blood sugar under control.
• Do not consume more than 1 or 2 alcoholic drinks per day.
• Try to manage your stress.

Follow your health care provider's recommendations to modify, treat, or control possible causes of secondary hypertension.

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.