Aldosterone
Adrenal hormone that regulates sodium, potassium and blood pressure
Also known as
Definition
Aldosterone is a hormone of the adrenal cortex. It prompts the kidneys to retain sodium and water and to excrete potassium, which keeps blood pressure stable. Its production is triggered partly by renin, which the kidneys release when blood pressure is low. That is why aldosterone is usually measured together with renin, often as the aldosterone-to-renin ratio. It can be measured in blood or in a 24-hour urine sample.
| Parameter | Value |
|---|---|
| Unit | pg/ml, pmol/l or ng/dl |
| Reference Range | No single range: the normal value depends on age, body position during the blood draw (lying, sitting, standing), salt intake and the lab method. The range printed on your report is what counts; your doctor interprets the result, usually together with renin. |
Agree on your personal target range with your doctor.
Conversion: 1 pg/ml ≈ 2.77 pmol/l; 1 ng/dl = 10 pg/ml ≈ 27.7 pmol/l.
↓ What a low value means
Low values can be related to adrenal insufficiency (Addison disease), congenital adrenal hyperplasia or a disorder of the pituitary or hypothalamus, for example after suddenly stopping steroid medicines taken for a long time. A very high-salt diet, diabetes, lead poisoning and some medicines such as nonsteroidal anti-inflammatory drugs (NSAIDs) are also linked to low values. Typical accompanying findings are low blood pressure, high potassium and low sodium. Discuss any deviation with your doctor.
↑ What a high value means
Elevated values can be related to primary aldosteronism (Conn syndrome), usually caused by a benign adrenal nodule. In secondary aldosteronism, the adrenal glands are healthy but another condition drives production, such as kidney disease, liver cirrhosis, heart failure, preeclampsia or dehydration. A very low-salt diet, overuse of diuretics or laxatives, and mineralocorticoid antagonists can also raise the value. Typical accompanying findings are high blood pressure and low potassium. Discuss any deviation with your doctor.
When to test
The test is usually ordered for high blood pressure that comes with low potassium, is hard to control with usual medicines or appears at a young age, as well as for abnormal sodium or potassium, a drop in blood pressure on standing, or an adrenal nodule found by chance. Body position, salt intake, licorice, intense exercise, stress and many medicines affect the value. Follow the practice's instructions and do not stop medicines without talking to your doctor.
Frequently asked questions
Why is aldosterone measured together with renin? +
Renin from the kidneys sits at the start of the feedback loop that triggers aldosterone production. Only the ratio of both values shows whether the adrenal glands make too much aldosterone on their own or are responding to an outside signal. That is why the aldosterone-to-renin ratio is often measured.
Why does licorice matter before the test? +
Natural licorice root in black licorice can distort the aldosterone measurement. MedlinePlus therefore mentions avoiding it for at least two weeks before the test. Your practice decides which preparation applies to you.
Does it matter whether I am lying down or standing? +
Yes. The aldosterone level in the blood changes with body position. The practice may therefore ask you to lie down or stand for a while before the blood draw, or measure in both positions.
Can salt affect the value? +
Yes. A very low-salt diet can raise aldosterone, a very high-salt diet can lower it. Sometimes the practice specifies a certain salt intake before the test or also measures sodium in urine.
Aldosterone
Sources
Last updated: October 05, 2026
This information is for orientation only and does not replace medical advice. Reference ranges can vary by laboratory, method and country.