What Is an Aldosterone Test?

Medically Reviewed by Carol DerSarkissian, MD on May 28, 2023
2 min read

If you’re having trouble with your blood pressure, your doctor might order an aldosterone test to help them figure out what’s going on.

When you get this test, a lab tech takes a small sample of your blood to measure how much of the hormone aldosterone is in your system. That result will help your doctor figure out what’s going on with your blood pressure.

It's a hormone that plays a big role in keeping your blood pressure in check.

Aldosterone balances the levels of sodium and potassium in your body. It signals to your organs, like your colon and kidneys, to put more sodium into your bloodstream or release more potassium into your pee.

Your adrenal glands, which are just above your kidneys, actually release the hormone.

When the level of aldosterone in your body is out of whack, it could lead to other health issues, including damage to your heart, brain, and kidneys.

If yours aren’t quite right, it can be caused by:

Conn’s syndrome: Also called primary hyperaldosteronism, this happens when your body makes too much aldosterone.

It leads to:

Conn's syndrome is usually the result of benign hyperplasia (enlargement) of both adrenals or small, benign tumors forming on your adrenal glands, which make aldosterone.

Addison’s disease: When your body doesn’t make enough of the hormone cortisol, it often doesn't make enough aldosterone, either. When this happens, you can have:

  • Low blood pressure
  • Higher potassium levels
  • An overall feeling of exhaustion

It can happen when there is damage to your adrenal glands.

Secondary hyperaldosteronism: It happens when your body makes more aldosterone in response to problems with other organs, like your kidneys, heart, or liver.

It can cause things like:

  • High blood pressure
  • Low potassium
  • Fluid retention

When your doctor orders an aldosterone test, they may also ask for blood tests for cortisol and another hormone called renin. The results can help tell your doctor if you have certain disorders:

If your tests show a high level of aldosterone, a low level of renin and a normal cortisol level, your doctor may diagnose you with Conn syndrome or hyperaldosteronism.

If your results show a high level of aldosterone and a high level of renin, you may have secondary hyperaldosteronism.

If your aldosterone and cortisol levels are lower than normal, and your renin level is high, you may be diagnosed with Addison’s disease.

If your aldosterone and renin levels are low, while your cortisol level is high, you may be diagnosed with Cushing syndrome.