Aldosterone-Renin Ratio Test
A blood test that looks for a hormone cause of high blood pressure.
Quick Summary
To check for primary aldosteronism in resistant or early high blood pressure, or low potassium.
Aldosterone, renin and their ratio.
Some blood pressure medicines may need to be changed beforehand; follow advice.
Overview
Primary aldosteronism is a treatable cause of high blood pressure.
Low potassium is a clue.
What It Measures
Aldosterone and renin
Hormone levels.
How It's Performed
- 01
Preparation
Usually no special preparation unless your doctor advises.
- 02
Blood sample
A small amount of blood is taken from a vein in your arm.
- 03
Afterwards
Press on the spot; a small bruise is common.
Interpreting Results & Next Steps
Discuss with Doctor
Normal ranges differ between laboratories; use the range on your report. Your doctor will explain what your result means and what happens next.
If values are High:
A high ratio suggests primary aldosteronism and needs further tests.
Sources and further reading
Last updated 21 October 2026. For more detail, see these trusted health organisations.
- Aldosterone Test(opens in a new tab) · MedlinePlus, US National Library of Medicine
- Renin test(opens in a new tab) · MedlinePlus, US National Library of Medicine