Preparation, Method & Test Results For Aldosterone in Urine

Submitted on March 27, 2012

Importance of Aldosterone Test

An aldosterone test is used to determine the level of the hormone, aldosterone, which is secreted by the adrenal glands. Aldosterone plays an important role in the regulation of sodium and potassium levels in the body, which helps to maintain blood pressure and control the balance of fluids in the blood. The adrenal glands are stimulated into releasing aldosterone when another hormone called renin is produced by the kidneys. High levels of both hormones are detected when the body is low in sodium and fluids.

Reason Why It is Conducted

An aldosterone test is done for the purpose of measuring the quantity of aldosterone that is being released by the adrenal glands. The test is helpful in detecting tumors and abnormal growths in the adrenal gland. Overactive functioning of the adrenal glands can also be detected.


Individuals taking the test are usually told to restrict sodium intake for two weeks before the test. The recommended amount of salt that can be taken is 2300 mg each day. Natural black licorice must also not be consumed for a couple of weeks prior to the test. The doctor must also be told about the type of medications that the individual may be taking. The individual may be advised to discontinue certain medicines which are likely to affect the test results. These include certain types of high blood pressure medications, hormones and diuretics. Any other concerns regarding the test can be discussed with the doctor in advance.

Method Used

The test begins by marking the time of the first urination in the morning. This urine is not collected though. Following this, the 24-hour period of urine collection begins. This can be done by the individual at home and a container for the collection is usually provided by the testing center. The urine must be collected in a smaller clean container and then poured into the larger container, which contains some preservatives. The insides of the container must not be touched with the fingers. This container must be placed in the refrigerator throughout the 24 hour period. The last time of urination that marks the end of the 24 hour period must be recorded. The urine sample must not get contaminated by pubic hair, menstrual blood, feces or toiler paper.

Interpretation of Test Results

A high amount of aldosterone in the urine test may indicate conn's syndrome, liver and kidney conditions, heart failure and preeclampsia, which is a condition that causes high blood pressure during pregnancy.

A low amount of aldosterone in the urine test could indicate addison's disease or kidney disease. Usually when determining the level of aldosterone through a urine test, renin levels of the body are also measured.

The test results may be not be accurate if the individual is pregnant, as during the third trimester, aldosterone levels increase. The aldosterone content in the blood also rises with increasing age.