High blood pressure, also known as hypertension, is classified as "essential (primary)" or "secondary.” Essential hypertension does not have an apparent cause. It may be due to such things as genetics (family members who have the disease) or lifestyle. Most people with high blood pressure have essential hypertension.

Secondary hypertension, on the other hand, is less common and is the result of another condition, such as:

Disorders of the adrenal gland (small organs, located above the kidneys, that create hormones), including Cushing's syndrome (a condition caused by an overproduction of cortisol); hyperaldosteronism (too much aldosterone); and pheochromocytoma (a rare tumor that causes oversecretion of hormones like adrenaline)
Kidney disease which may include polycystic kidney disease, kidney tumor, kidney failure, or a narrow or blocked main artery supplying the kidney
Drugs such as corticosteroids (anti-inflammatory drugs like prednisone), nonsteroidal anti-inflammatory drugs (Motrin, Aleve, Naprosyn, Celebrex), weight loss drugs (such as Meridia), cold medications that include decongestants, like pseudoephedrine, birth control pills (the estrogen component), and migraine medications (such as Imitrex).
Sleep apnea, a condition in which a person has brief spells in which he stops breathing during sleep. About half of patients with this condition have high blood pressure.
Coarctation of the aorta, a birth defect in which the aorta is narrowed
Preeclampsia, a condition related to pregnancy
Thyroid and parathyroid problems

How Is Secondary Hypertension Diagnosed?

After you are diagnosed with hypertension, your doctor may perform other tests such as blood and urine screening to make sure you don't have secondary hypertension.

How Is Secondary Hypertension Treated?

In order to treat secondary hypertension, your doctor will address the condition or disorder that is causing the hypertension (adrenal gland disorder, kidney disease, sleep apnea, etc.) and try to correct that.

In some cases, this may mean that you will have to undergo surgery; for example, if you have a kidney disorder or coarctation of the aorta. Not all patients will be eligible for surgery, however. Your doctor may also choose to treat you with antihypertensive drug therapy, whether or not you have surgery.

If you have secondary hypertension that is caused by a drug, your doctor may suggest that you stop taking or decrease the dose of the drug.

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