What is secondary hypertension?

Most of the time, high blood pressure (hypertension) occurs by itself. This kind of high blood pressure is called essential hypertension. High blood pressure caused by some other disease or condition is called secondary hypertension. Most cases of secondary hypertension are related to hormone or kidney problems.

Three or more blood pressure readings higher than 140 (systolic)/90 (diastolic) indicate high blood pressure. The systolic (pumping) pressure, diastolic (resting) pressure, or both may be higher than normal.

High blood pressure, if not treated, will eventually lead to the development of heart problems, kidney damage, a stroke, or all three.

How does it occur?

Many diseases, medical conditions, and medications cause secondary hypertension, including:

• narrowing of the arteries in the kidneys

• narrowing of the aorta, a large blood vessel that supplies blood to the lower body

• several types of kidney disease

• excess secretion of a hormone called aldosterone from the adrenal gland

• tumor of the adrenal gland

• Cushing's syndrome, a hormone disorder in which there is an excessive amount of corticosteroids in the blood

• increased pressure in the skull as with a brain tumor

• diseases of connective tissue such as lupus (SLE)

• drugs such as estrogen, oral contraceptives, and amphetamines

• abuse of drugs such as amphetamines, alcohol, or diet pills

• pregnancy.

What are the symptoms?

High blood pressure itself usually doesn't cause obvious symptoms. However, secondary hypertension may begin abruptly with severe symptoms. Often the disease causing the high blood pressure causes the symptoms. Symptoms may include:

• headaches

• dizziness

• fatigue

• restlessness and sleeplessness

• nosebleeds

• palpitations or an awareness of your heartbeat

• general feeling of ill health

• swelling in the legs

• muscle weakness

• frequent urination

• increased thirst

• round or 'moon' face, excess body and facial hair, and weight gain if the high blood pressure is caused by Cushing's syndrome.

How is it diagnosed?

Your health care provider will ask about your symptoms and medical history and will do a physical exam. Tests of your blood, chest x-rays, and an electrocardiogram may be done. Your provider may want to measure your blood pressure on three different days when you are relaxed and not in a hurry and have not had alcohol for 72 hours.

The medical history is an important part of diagnosis. Your health care provider will ask about your personal and family history of high blood pressure and heart or kidney disease.

How is it treated?

Secondary hypertension is treated by treating the underlying cause. For example, if you have high blood pressure caused by Cushing's syndrome, treatment for Cushing's will lower your blood pressure.

How long will the effects last?

If the cause can be diagnosed and treated, your blood pressure should improve. You may be able to cut down or stop taking your medicines if your underlying condition is treated.

How can I take care of myself?

• Take medications as prescribed. Don't abruptly stop or decrease your medications without asking your health care provider. It is dangerous to suddenly stop taking certain blood pressure medications.

• If you smoke, quit.

• Reduce the salt in your diet according to your health care provider's advice.

• Start an exercise program you can do regularly (such as biking or walking), with the approval of your health care provider.

• Lose weight if necessary.

• Limit the amount of alcohol you drink.

• Reduce stress or learn to use stress management techniques.

• Monitor your blood pressure regularly. You can do it yourself or have a health care professional check it. Keep a chart of the readings.

• See your health care provider as often as he or she recommends.

What can be done to help prevent secondary hypertension?

Most of the conditions that cause secondary hypertension cannot be prevented. However, regular checkups can help detect many conditions before they become serious, including those that can result in high blood pressure.