Hyperaldosteronism can be caused by a tumor in the adrenal gland or may be a response to some diseases.
High aldosterone levels can cause high blood pressure and low potassium levels. Low potassium levels may cause weakness, tingling, muscle spasms, and periods of temporary paralysis.
Doctors measure the levels of sodium, potassium, and aldosterone in the blood.
Sometimes, a tumor is removed, or people take drugs that block the action of aldosterone.
(See also Overview of the Adrenal Glands Overview of the Adrenal Glands The body has two adrenal glands, one near the top of each kidney. They are endocrine glands, which secrete hormones into the bloodstream. Each adrenal gland has two parts. Medulla: The inner... read more .)
Aldosterone, a hormone produced and secreted by the adrenal glands, signals the kidneys to retain more sodium and excrete more potassium. Aldosterone production is regulated partly by the hormone adrenocorticotropic hormone (ACTH, also known as corticotropin), which is secreted by the pituitary gland Overview of the Pituitary Gland The pituitary is a pea-sized gland that is housed within a bony structure (sella turcica) at the base of the brain. The sella turcica protects the pituitary but allows very little room for expansion... read more , but mainly through the renin-angiotensin-aldosterone system (see figure Regulating Blood Pressure Regulating Blood Pressure: The Renin-Angiotensin-Aldosterone System ). Renin, an enzyme produced in the kidneys, controls the activation of the hormone angiotensin, which stimulates the adrenal glands to produce aldosterone.
Hyperaldosteronism can be caused by a tumor (usually a noncancerous adenoma) in the adrenal gland (a condition called Conn syndrome or primary hyperaldosteronism), although sometimes both glands are involved and are overactive. Sometimes hyperaldosteronism is a response to something else (a condition called secondary hyperaldosteronism), for example, certain diseases, such as narrowing of one of the arteries to the kidneys.
Eating large amounts of real licorice can cause all the symptoms of hyperaldosteronism. Real licorice contains a chemical that can act as though there is too much aldosterone. However, most candy sold as "licorice" is artificially flavored and contains little or no real licorice.
Symptoms of Hyperaldosteronism
Doctors suspect hyperaldosteronism in people with high blood pressure who are found to have low potassium levels. Low potassium levels Hypokalemia (Low Level of Potassium in the Blood) In hypokalemia, the level of potassium in blood is too low. A low potassium level has many causes but usually results from vomiting, diarrhea, adrenal gland disorders, or use of diuretics. A... read more often cause no symptoms but may lead to weakness, tingling, muscle spasms, and periods of temporary paralysis. Some people become extremely thirsty and urinate frequently.
Diagnosis of Hyperaldosteronism
Measurement of sodium, potassium, and hormone levels in the blood
Imaging tests of the adrenal glands
Doctors who suspect hyperaldosteronism test the levels of sodium and potassium in the blood to see whether the potassium level is low. However, sometimes people with hyperaldosteronism have a normal potassium level. The sodium level may be mildly increased.
Doctors also measure renin and aldosterone levels. If the aldosterone level is high, spironolactone or eplerenone, drugs that block the action of aldosterone, may be given to see if the levels of sodium and potassium return to normal. Doctors also measure the levels of renin. In Conn syndrome, the levels of renin are also very low because they are suppressed by high levels of aldosterone. In secondary hyperaldosteronism, the levels of renin are high, and they stimulate production of aldosterone.
When too much aldosterone is being produced but renin levels are very low, doctors examine the adrenal glands for a noncancerous tumor (adenoma). Computed tomography (CT) or magnetic resonance imaging (MRI) can be helpful, but sometimes blood samples from each of the adrenal glands must be tested to determine the source of the hormone.
Treatment of Hyperaldosteronism
For tumors of the adrenal glands, removal of the tumor
Sometimes aldosterone-blocking drugs
If a tumor is found, it can usually be surgically removed. When the tumor is removed, the low potassium level almost always returns to normal, while blood pressure returns to normal about 50 to 70% of the time.
If no tumor is found and both glands are overactive, partial removal of the adrenal glands may not control high blood pressure, and complete removal will cause Addison disease Adrenal Insufficiency In adrenal insufficiency, the adrenal glands do not produce enough adrenal hormones. Adrenal insufficiency may be caused by a disorder of the adrenal glands, a disorder of the pituitary gland... read more , requiring treatment with corticosteroids for life. However, spironolactone or eplerenone can usually control the symptoms, and drugs for high blood pressure are readily available (see table Antihypertensive Drugs Antihypertensive Drugs ). Spironolactone can often cause breast enlargement (gynecomastia Breast Disorders in Men Breast disorders occur infrequently in men. Breast disorders include Breast enlargement Breast cancer Breast enlargement in males is called either gynecomastia or pseudogynecomastia. Gynecomastia... read more ), decreased sex drive, and erectile dysfunction in men by blocking the effects of testosterone.
Rarely do both adrenal glands have to be removed.