An aldosterone test measures the level of aldosterone (a hormone made by the adrenal glands), in the blood. 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 tumour 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.
An aldosterone test is done to:
An aldosterone test is often done at the time of a routine blood test. You do not need to do anything before having routine blood tests.
If you are having follow-up aldosterone blood tests, your doctor may give you the following instructions:
Many medicines may change the results of this test. Be sure to tell your doctor about all the non-prescription and prescription medicines you take. You may be asked to stop taking some medicines for 2 weeks before the test. These include hormones (such as progesterone and estrogens), corticosteroids, diuretics, and many medicines used to treat high blood pressure, especially spironolactone (Aldactone), eplerenone (Inspra), and beta-blockers.
The amount of aldosterone in blood changes depending on whether you are standing up or lying down. If initial results show a problem, repeat tests may be done in different positions and under different conditions, such as not eating before the test or eating foods that contain a specific amount of salt. Your doctor may ask you to have your blood drawn at a certain time because aldosterone levels are highest in the early morning.
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?).
The health professional taking a sample of your blood will:
The blood sample is taken from a vein in your arm. An elastic band is wrapped around your upper arm. It may feel tight. You may feel nothing at all from the needle, or you may feel a quick sting or pinch.
There is very little chance of a problem from having blood sample taken from a vein.
Aldosterone levels in a blood sample also change depending on whether you are standing up or lying down at the time the blood is taken. Blood aldosterone levels will be higher if you are standing or sitting up for 2 hours before the test.
Normal values may vary from lab to lab. Results are usually available in 2 to 5 days.
|Standing or sitting down|| |
4–48 nanograms per decilitre (ng/dL) or 0.11–1.33 nmol/L
7–30 ng/dL or 0.19–0.83 nmol/L
3–35 mg/dL or 0.08–0.97 nmol/L
2–22 ng/dL or 0.06–0.61 nmol/L
3–16 ng/dL or 0.08–0.44 nmol/L
An overgrowth of normal cells in the adrenal glands (called adrenal hyperplasia) or a tumour of the adrenal glands affects the adrenal glands directly and causes a condition called primary aldosteronism. Certain diseases such as heart failure, cirrhosis, or kidney disease can also cause high aldosterone levels, but this is a normal response by the adrenal glands. These diseases cause secondary aldosteronism.
|Primary hyperaldosteronism (Conn's syndrome)|| |
|Secondary hyperaldosteronism|| |
High aldosterone levels can be caused by:
Symptoms of a high aldosterone level include high blood pressure, muscle cramps and weakness, numbness or tingling in the hands, and low levels of potassium in the blood.
Addison's disease may cause low aldosterone levels.
Reasons you may not be able to have the test or why the results may not be helpful include:
Other Works Consulted
- Chernecky CC, Berger BJ (2008). Laboratory Tests and Diagnostic Procedures, 5th ed. St. Louis: Saunders.
- Fischbach FT, Dunning MB III, eds. (2009). Manual of Laboratory and Diagnostic Tests, 8th ed. Philadelphia: Lippincott Williams and Wilkins.
- Pagana KD, Pagana TJ (2010). Mosby’s Manual of Diagnostic and Laboratory Tests, 4th ed. St. Louis: Mosby Elsevier.
|Primary Medical Reviewer||E. Gregory Thompson, MD - Internal Medicine|
|Primary Medical Reviewer||Brian D. O'Brien, MD - Internal Medicine|
|Specialist Medical Reviewer||Alan C. Dalkin, MD - Endocrinology|
|Last Revised||September 30, 2010|
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