Aldosterone Test
Reviewed
Also called: aldosterone, serum, aldosterone urine, aldosterone-renin ratio test, aldosterone-plasma renin activity
An aldosterone test measures the amount of aldosterone (ALD) in your blood or urine (pee).
Specimen: Blood or urine
Why this test may be ordered
- To find out whether too much ALD is causing high blood pressure that occurs with low potassium, doesn't improve with usual medicines, or develops at a young age.
- To help diagnose adrenal gland disorders.
- To find the cause of abnormal sodium or potassium levels on an electrolyte test.
- To find the cause of orthostatic hypotension (low blood pressure causing dizziness when standing up).
Preparation and collection
You may need to stop taking certain medicines for a period of time before the test. So, be sure to tell your provider everything you're taking. But don't stop taking any prescribed medicine unless your provider tells you to stop. You may also be asked to limit the amount of salt you eat each day for about two weeks before your test. You should not eat natural black licorice for at least two weeks before your test, because it can affect your results.
An aldosterone (ALD) test uses a sample of blood or urine. The amount of ALD in your blood changes depending on whether you are standing up or lying down. So, you may be asked to lie down or stand for a period of time before the test. For an ALD urine test, your provider may ask you to collect all urine during a 24-hour period.
There is very little risk to having a blood test. You may experience slight pain or bruising at the spot where the needle was put in, but most symptoms go away quickly. There are no known risks to having a urine test.
Understanding results
If your ALD levels are too high or too low, your blood pressure may also be too high or too low.
- Higher than normal aldosterone levels: In general, higher than normal amounts of ALD may mean you have primary or secondary aldosteronism. Conditions that can cause high ALD levels include: Kidney disease, Cirrhosis of the liver, Heart failure, Preeclampsia, a type of high blood pressure that happens in pregnancy, Dehydration. Limitation: To understand what your test results mean, your provider will consider your aldosterone (ALD) levels along with the results of other tests. Next step: Ask your provider to explain what your results say about your health.
- Lower than normal aldosterone levels: In general, lower than normal amounts of ALD may mean you have: Addison disease (also called adrenal insufficiency). Congenital adrenal hyperplasia (CAH), a group of genetic disorders you're born with. Limitation: Low levels of ALD may also be linked to: Certain other health conditions, such as diabetes and lead poisoning, Certain medicines, including non-steroidal anti-inflammatory drugs (NSAIDs), such as ibuprofen, and some heart failure medicines. Next step: Ask your provider to explain what your results say about your health.
- Results must be interpreted together with other tests (e.g., renin, electrolytes).
- Levels change with posture (lying vs. standing).
- Certain medicines, salt intake, and natural black licorice can affect results.
What to do next
Ask your provider to explain what your results say about your health.
- What do my aldosterone test results mean in combination with my other test results?
- Do I need to adjust my medicines or diet before the test?
- What follow-up tests or steps are recommended based on my results?
Evidence source
Source: U.S. National Library of Medicine (MedlinePlus). Practices and reference ranges may differ in your country.