Secondary Hypertension

Secondary hypertension is chronically high blood pressure resulting from one or several underlying conditions. These are most often related to kidney disease, hormonal imbalances (or diseases causes specific hormone imbalances), narrowing of the aorta, and drug treatments.

Secondary Hypertension

Secondary Hypertension Related to Kidney Disease
The kidney is an essential organ for maintaining normal blood pressure. In fact, the possibility of renal disease should be considered in all patients diagnosed with hypertension. Secondary hypertension occurs when the kidney becomes diseased which reduces its effectiveness at maintaining normal blood pressure or when the blood supply to each kidney is reduced due to narrowing of the renal blood vessels. All forms of chronic and some acute kidney disease can cause secondary hypertension. Secondary hypertension can often be managed by restriction of salt and water intake and by careful dialysis.

Secondary Hypertension Related to Hormonal Imbalance
Many of the important hormones maintaining normal blood pressure are released from the kidney and the adrenal glands. Normally, the kidney releases a hormone called Renin which functions to retain water and to narrow blood vessels in response to low blood volume or dehydration. In secondary hypertension, renin release is uncontrolled causing excessive water retention and inappropriate constriction of blood vessels. This causes high blood pressure. The adrenal glands secrete a wide array of hormones. Tumors of the adrenal gland can cause uncontrolled release of these hormones resulting in secondary hypertension. Cushing's syndrome (hypersecretion of cortisol) and Conn's syndrome (hypersecretion of aldosterone) are examples of adrenal gland diseases triggering secondary hypertension.

Secondary Hypertension Related to Narrowing of the Aorta
The aorta is the main artery leaving the heart and distributing oxygenated blood to the entire body. This vessel is the largest in the body and is very elastic. When the aorta becomes narrowed and stiff less blood can pumped to the body. This causes blood to "back up" resulting in secondary hypertension. A characteristic feature of this cause of secondary hypertension is raised blood pressure detectable in either arm, but not in the legs. Also, the femoral pulse is often delayed relative to the radial pulse.

Secondary Hypertension Related to Drug therapy
Drugs are prescribed for many different conditions and all prescriptions have some side effects. Corticosteroids, some types of contraceptive pill and some non-steroidal anti-inflammatory drugs can induce secondary hypertension. Contact your physician or pharmacist to discuss potential side effects.

Secondary hypertension arises from existing conditions or as side effects of drug therapy. Managing the disease can often reduce secondary hypertension to normal values.