Adrenal Diseases - Hyperaldosteronism
The Facts You Need To Know
On This Page:
What is Hyperaldosteronism?
What causes Hyperaldosteronism?
How is Hyperaldosteronism diagnosed?
How is Hyperaldosteronism treated?
Hyperaldosteronism Fact Sheet (pdf)
What is Hyperaldosteronism?
Hyperaldosteronism is a disease caused by an
excess production of the normal adrenal hormone, aldosterone. This hormone
is responsible for sodium and potassium balance, which then directly
controls water balance to maintain appropriate blood pressure and blood
volume.
Hyperaldosteronism causes high blood pressure
and a low serum potassium. The serum sodium is usually in the normal range.
People with a deficiency of aldosterone,
especially found in association with cortisol deficiency in Addison’s
disease, have low blood volume and therefore low blood pressure, low sodium
and high potassium. Just the opposite is seen in hyperaldosteronism.
This is a rare disease and is an unusual cause of hypertension. It is
usually considered by physicians if they find an unexpectedly low potassium
in a person being treated for hypertension.
It generally causes no other
specific symptoms or signs. The physical examination in people with hyperaldosteronism is totally normal.
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What Causes Hyperaldosteronism?
There are two types of
hyperaldosteronism:
1) It can occur from hyperplasia (enlargement), of both
adrenal glands
2) It can be caused by a benign (rarely malignant) tumor of one of
the adrenal glands. When the cause is a single adrenal tumor, it is labeled
Conn’s Syndrome.
How is Hyperaldosteronism diagnosed?
When hyperaldosteronism is considered by a
physician, tests are done to look for an excess of the hormone aldosterone
in the blood and urine, and also a suppressed plasma renin. Other tests,
looking at other adrenal steroid hormones, can be very useful as well as
tests looking for the normal physiologic changes in hormones in the morning
and evening, as well as responses to sodium challenge or sodium restriction.
These tests can help to differentiate the
bilateral hyperplasia from an adrenal tumor. When a tumor is suspected,
radiologic proof with a CT scan or MRI will usually help to confirm the
diagnosis.
How is Hyperaldosteronism Treated?
The treatment depends on the cause. If there is
a single tumor, surgical removal of that tumor can cure the disease. The
remaining adrenal gland is usually normal and individuals with this form of
the disease will have enough adrenal hormone production from the remaining
gland to live normally.
Unfortunately, quite often there is still some
residual hypertension even after the surgery, so sometimes antihypertensive
medication is still necessary.
If bilateral hyperplasia is the cause of
hyperaldosteronism, this is treated with specific medications that block the
effect of aldosterone. There are three such medications: spironolactone (Aldactone), eplerenone (Inspra) and amiloride (Midamor). These medications are very effective, but are sometimes used in combination with other antihypertensive medications for the management of hypertension in individuals with hyperaldosteronism.
The answers above were provided by
Dr. Paul Margulies, MD, FACP, FACE,
NADF Medical Director
Clinical Associate Professor of Medicine, New York University Medical School
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