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What is it?

Conn’s syndrome is another name for primary hyperaldosteronism, an endocrine disorder characterized by excessive secretion of the hormone aldosterone from the adrenal glands. This overproduction leads to the retention of sodium and loss of potassium in the body, resulting in high blood pressure (hypertension).  The adrenal glands are small triangular organs located on the top of the kidneys. They are part of the endocrine system, a group of glands that produce and secrete hormones that act on and regulate many systems throughout the body.

Aldosterone is a hormone that plays an important role in maintaining blood volume, pressure, and electrolyte balance. Its production is normally regulated by renin, an enzyme produced in the kidneys. When renin increases (due to low blood pressure, decreased blood flow to the kidneys or to a sodium deficiency), aldosterone increases; when renin decreases, aldosterone decreases.In Conn’s syndrome, an individual can produce excess aldosterone because of one or more benign adrenal tumors, by over activity of both glands called bilateral adrenal hyperplasia, or for unknown reasons (idiopathic). Rarely, it is caused by a cancerous (malignant) adrenal tumor. Regardless of the cause, aldosterone is produced despite low renin levels

Increased aldosterone can lead to hypokalaemia, increased blood pH (alkalosis), and high blood pressure. It may cause a few nonspecific symptoms such as  weakness, fatigue, and muscle cramps. A healthcare practitioner may suspect primary aldosteronism in a person who has high blood pressure that is difficult to control, requires multiple blood pressure medications, and/or does not respond to standard treatments.

The presence of hypokalaemia in a person with high blood pressure suggests the need to look for primary hyperaldosteronism although the most common cause of this pattern is as a side-effect of some of the drugs used to treat high blood pressure.

Diagnosing Conn’s syndrome is important because it represents one of the few causes of high blood pressure that is potentially curable. Although anyone can get primary hyperaldosteronism, it commonly occurs in adults between the ages of 30 and 50 and is more common in women than men. It can sometimes be difficult to diagnose as patients may have variable symptoms or no symptoms at all. Suspicion of Conn’s syndrome may be raised in patients who are resistant to the standard therapies used to treat high blood pressure.

Secondary aldosteronism, must be distinguished from primary aldosteronism. Secondary aldosteronism is caused by problems outside the adrenal glands that lead to the glands releasing too much aldosterone.It can occur as a result of anything that increases renin levels, such as decreased blood flow to the kidneys, low blood pressure, or low sodium levels in the urine. The most important cause is narrowing of the blood vessels that supply the kidney, termed renal artery stenosis. Other causes of secondary hyperaldosteronism include congestive heart failurecirrhosiskidney disease, and toxaemia of pregnancy.

 


Last Review Date: July 1, 2018