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Primary hyperaldosteronism (Conn's syndrome or aldosterone-producing adrenal tumor)

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What is primary hyperaldosteronism?

AldosteroneAldosterone - a mineralocorticoid that controls blood pressure is a hormoneHormone - a chemical made by a gland that travels in the bloodstream and "tells organs what to do." made by the adrenal gland that helps control the blood pressure by changing the levels of electrolytes such as sodium and potassium in the blood. Too much aldosterone causes the body to hold onto sodium and water and to get rid of potassium in unsafe amounts. This, in turn increases the amount of fluid in your body, and therefore increases your blood pressure.

Primary hyperaldosteronismPrimary hyperaldosteronism - a disease where too much aldosterone is being made is a disease in which one or both adrenal glands produce too much aldosterone. The word "primary" means that the condition is caused by a problem in the adrenal glands. Problems outside of the adrenal glands can also lead to too much aldosterone, but these conditions are called secondary hyperaldosteronism. Primary hyperaldosteronism can be caused by either unilateral disease (i.e. hyperactivity in one adrenal gland) or bilateral disease (i.e. hyperactivity in both adrenal glands). The two most common causes of primary hyperaldosteronism are an aldosterone-producing adrenal tumor and bilateral adrenal hyperplasia.

Causes of Primary Hyperaldosteronism
Most Common:
Unilateral adrenal gland adenoma (2/3)
Bilateral adrenal gland hyperplasia (1/3)
Less Common:
Unilateral adrenocortical carcinoma (<1%)
Unilateral adrenal gland hyperplasia (<1%)
Familial hyperaldosteronism, Types I and II (<1%)
Figure 1: Causes of Primary Hyperaldosteronism

An aldosterone-producing tumor or "aldosteronoma" is a benign tumor in one of the adrenal glands that makes too much aldosterone. In bilateral hyperplasia, both adrenal glands are hyperactive and make too much aldosterone. Less common causes of primary hyperaldosteronism include unilateral adrenal hyperplasia (where one of the adrenal glands is hyperactive but there is no clear tumor), malignant aldosterone-producing tumor (a rare type of adrenocortical cancer that makes too much aldosterone), and genetic syndromes such as familial hyperaldosteronism types I and II in which both adrenal glands make too much aldosterone.

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