Reasons, Preparation and Test Results For Aldosterone In Blood

Submitted on March 27, 2012

Aldosterone is a hormone that is produced by the adrenal glands. It helps to control the levels of potassium and sodium in the body. This aids in the regulation of blood pressure. It also assists in maintaining the levels of electrolytes and fluids in the bloodstream. The kidney releases a hormone called rennin, which stimulates the production of aldosterone by the adrenal glands. When the body is attempting to conserve sodium and fluids, there is usually a high content of rennin and aldosterone in the blood. Generally, when aldosterone content is being tested, a renin activity test is also performed.

Reasons for Performing the Aldosterone in Blood Test

An aldosterone test is done to measure the content of aldosterone that is released by the adrenal glands into the blood. Tumors present in the adrenal glands can also be detected through this test. Abnormal growths and over-activity of the adrenal glands may result in decreased levels of potassium in the blood and high blood pressure. The test also serves to verify these causes.


There is no preparation required prior to an aldosterone test as it generally performed during a usual blood test. For follow up tests the doctor may advise the individual to consume foods with moderate sodium content for a couple of weeks before the test. A diet that is low in sodium can also elevate aldosterone levels, and hence the doctor must be notified if the individual is on such a diet. The doctor must also be informed about any medications that the individual is taking as there are several medications that can affect the test results. Hormone supplements, diuretics, corticosteroids and many high blood pressure medications may need to be discontinued for a period of two weeks before the test. The aldosterone content varies depending on whether the individual is standing upright or lying down. As such the test may be taken with the individual in varied positions if the initial results were affected. The person may also be asked to take the test at early morning when the aldosterone levels are higher or he may be told to restrict eating before the test.


A blood sample is obtained from a vein in the upper arm of the individual.

Test Results

The test results are generally available in two to five days. High levels of aldosterone in the blood may indicate conn's syndrome, kidney or liver disease and heart problems. High levels of aldosterone in the blood also cause primary hyperaldosteronism. Low levels of aldosterone in the blood could indicate addison's disease.

Other Considerations

In certain cases, the test may not prove helpful. These instances include pregnancy as aldosterone levels are high during the third trimester, intake of certain medications, emotional stress or strenuous exercise and age, as the level of aldosterone reduces as the age increases.