Aldosterone in Urine
An aldosterone test measures the level of aldosterone (a hormone made by the adrenal glands), in the urine. Aldosterone helps regulate sodium and potassium levels in the body. This helps control blood pressure and the balance of fluids and electrolytes in the blood.
The kidney hormone renin normally stimulates the adrenal glands to release aldosterone. High levels of both renin and aldosterone are normally present when the body is trying to conserve fluid and salt (sodium). When a tumor that makes aldosterone is present, your aldosterone level will be high while a renin level will be low. Usually a renin activity test is done when the aldosterone level is measured.
Why It Is Done
An aldosterone test is done to:
- Measure the amount of aldosterone released into the body by the adrenal glands.
- Check for a tumor in the adrenal glands.
- Find the cause of high blood pressure or low potassium levels. This is done when overactive adrenal glands or an abnormal adrenal growth are suspected.
How To Prepare
Eat foods with a normal amount of sodium (2,300 mg per day) for at least 2 weeks before the test. Do not eat foods that are very salty, such as bacon, canned soups and vegetables, olives, bouillon, soy sauce, and salty snacks like potato chips or pretzels. A low-salt diet can also increase aldosterone levels. Tell your doctor if you are on a low-salt food plan.
Do not eat natural black licorice for at least 2 weeks before an aldosterone test.
Many medicines may change the results of this test. Be sure to tell your doctor about all the nonprescription and prescription medicines you take. You may be asked to stop taking some medicines for about 2 weeks before the test. These include hormones (such as progesterone and estrogen), corticosteroids, diuretics, and many medicines used to treat high blood pressure, especially spironolactone (Aldactone) and eplerenone (Inspra).
Talk to your doctor about any concerns you have regarding the need for the test, its risks, how it will be done, or what the results will mean. To help you understand the importance of this test, fill out the medical test information form(What is a PDF document?).