| Subject | Contents |
| Definition | A test that measures the amount of aldosterone eliminated in the urine in a day (see the blood aldosterone test). |
| Alternative Names | Aldosterone - urine |
| How the test is performed | A 24 hour urine sample is needed. The health care provider will instruct you, if necessary, to discontinue drugs that may interfere with the test. On day 1, urinate into the toilet upon arising in the morning. Collect all subsequent urine (in a special container) for the next 24 hours. On day 2, urinate into the container in the morning upon arising. Cap the container. Keep it in the refrigerator or a cool place during the collection period. Label the container with your name, the date, the time of completion, and return it as instructed. Infant: Thoroughly wash the area around the urethra. Open a urine collection bag (a plastic bag with an adhesive paper on one end), and place it on your infant. For males, the entire penis can be placed in the bag and the adhesive attached to the skin. For females, the bag is placed over the labia. Place a diaper over the infant (bag and all). The infant should be checked frequently and the bag changed after the infant has urinated into the bag. For active infants, this procedure may take a couple of attempts -- lively infants can displace the bag, causing an inability to obtain the specimen. The urine is drained into the container for transport to the laboratory. Deliver it to the laboratory or your health care provider as soon as possible upon completion. The lab analyzes the sample for the amount of aldosterone. |
| How to prepare for the test | No special preparation is necessary for this test, but if the collection is being taken from an infant, a couple of extra collection bags may be necessary. |
| How the test will feel | The test involves only normal urination, and there is no discomfort. |
| Why the test is performed | The test evaluates the excretion of aldosterone in the urine. Aldosterone is a hormone secreted by the adrenal gland which acts on the kidney to regulate salt and potassium balance. |
| Normal Values | Normal values range from 6 to 25 mcg/24 hours. (This depends on the amount of sodium excreted by the body. The greater the amount of sodium, the lower the level of aldosterone .) Note: mcg/24 hr = micrograms per 24 hours |
| What abnormal results mean | Greater than normal levels of aldosterone may indicate:Conn's syndrome (aldosterone-secreting adenoma) bilateral adrenal hyperplasiaprimary aldosteronism secondary aldosteronism due to a variety of causes including: diuretic abuse laxative abuse cirrhosisheart failure Lower than normal levels may indicate: Addison's disease |
| What the risks are | There are no risks. |
| Special considerations | The results may be questionable, if the renal function is not normal. Nonpharmacological factors that can affect aldosterone measurements include: strenuous exercise , acute stress , high- or low-sodium diet, and pregnancy . Drugs that can increase aldosterone measurements include: lithium, spironolactone, and verapamil. Drugs that can decrease aldosterone measurements include: ACE inhibitors, NSAIDS, ranitidine, and propranolol. |
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