Aldosterone in Blood Test
Test Overview
An aldosterone test measures the level of aldosterone (a hormone, Opens dialog made by the adrenal glands, Opens dialog), in the blood. Aldosterone helps regulate sodium, Opens dialog and potassium, Opens dialog levels in the body. This helps control blood pressure and the balance of fluids and electrolytes, Opens dialog in the blood.
The kidney hormone renin, Opens dialog 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 tumor 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:
- Measure the amount of aldosterone released into the body by the adrenal glands.
- Check for a tumor in the adrenal glands.
- Find the cause of high blood pressure or low blood potassium levels. This is done when overactive adrenal glands or an abnormal adrenal growth are suspected.
An aldosterone test is often done at the time of a routine blood test. You don't 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:
- Eat foods with a normal amount of sodium (2,300 mg, Opens dialog per day) for 2 weeks before the test. Do not eat foods that are very salty, such as bacon, canned soups and vegetables, olives, bouillon, soy sauce, and salty snacks like potato chips or pretzels. A low-salt diet can also increase aldosterone levels. Tell your doctor if you are on a low-salt food plan.
- Do not eat natural black licorice for 2 weeks before this test.
Many medicines may change the results of this test. Be sure to tell your doctor about all the nonprescription 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, Opens dialog), corticosteroids, Opens dialog, diuretics, Opens dialog, and many medicines used to treat high blood pressure, especially spironolactone (Aldactone), eplerenone (Inspra), and beta-blockers, Opens dialog.
The amount of aldosterone in blood changes depending on whether you are standing up or lying down. If your 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. That's because aldosterone levels are highest in the early morning.
When a blood sample is taken, you may feel nothing at all from the needle. Or you might feel a quick sting or pinch.
There is very little chance of having a problem from this test. When a blood sample is taken, a small bruise may form at the site.
Results are usually available in 2 to 5 days.
Normal
Each lab has a different range for what's normal. Your lab report should show the range that your lab uses for each test. The normal range is just a guide. Your doctor will also look at your results based on your age, health, and other factors. A value that isn't in the normal range may still be normal for you.
High values
High aldosterone levels can be caused by:
- A tumor in the adrenal glands (Conn's syndrome, Opens dialog).
- Kidney disease.
- Liver disease.
- Heart failure.
- Dehydration.
- A condition during pregnancy that causes high blood pressure (preeclampsia, Opens dialog).
An overgrowth of normal cells in the adrenal glands (called adrenal hyperplasia) or a tumor of the adrenal glands affects the adrenal glands directly and causes a condition called primary aldosteronism. Certain diseases, such as heart failure, Opens dialog, cirrhosis, Opens dialog, and kidney disease, can also cause high aldosterone levels, but this is a normal response by the adrenal glands. These diseases cause secondary aldosteronism.
Condition | Aldosterone | Renin |
|---|---|---|
Primary hyperaldosteronism (Conn's syndrome) | High | Low |
Secondary hyperaldosteronism | High | High |
Low values
Addison's disease, Opens dialog and some types of kidney disease may cause low aldosterone levels.
Current as of: April 30, 2024
Author: Ignite Healthwise, LLC Staff
Clinical Review Board
All Healthwise education is reviewed by a team that includes physicians, nurses, advanced practitioners, registered dieticians, and other healthcare professionals.
Current as of: April 30, 2024
Author: Ignite Healthwise, LLC Staff
Clinical Review Board
All Healthwise education is reviewed by a team that includes physicians, nurses, advanced practitioners, registered dieticians, and other healthcare professionals.
This information does not replace the advice of a doctor. Ignite Healthwise, LLC, disclaims any warranty or liability for your use of this information. Your use of this information means that you agree to the Terms of Use. Learn how we develop our content.