Aldosterone in Urine
An aldosterone test measures the level of
hormone made by the
adrenal glands), in the urine. Aldosterone helps
potassium levels in the body. This helps control blood
pressure and the balance of fluids and
electrolytes in the blood.
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
- 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
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
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?).
How It Is Done
- You start collecting your urine in the morning.
When you first get up, empty your bladder but do not save this urine. Write
down the time that you urinated to mark the beginning of your 24-hour
- For the next 24 hours, collect all your urine.
Your doctor or lab will usually provide you with a large container that holds
about 1 gal (4 L). The
container has a small amount of preservative in it. Urinate into a small, clean
container and then pour the urine into the large container. Do not touch the
inside of the container with your fingers.
- Keep the large container
in the refrigerator for the 24 hours.
- Empty your bladder for the
final time at or just before the end of the 24-hour period. Add this urine to
the large container and record the time.
- Do not get toilet paper,
pubic hair, stool (feces), menstrual blood, or other foreign matter in the