Aldosterone and renin test
An aldosterone and renin test is carried out to check whether the levels of these two substances are normal.
Renin is an enzyme (protein) that's released into the blood by the kidney in response to stress.
It reacts with a substance from the liver to produce angiotensin, which causes the blood vessels to narrow and your blood pressure to increase.
Renin also increases the production of aldosterone, which is a hormone that acts on the kidney to help control the body's salt and water balance.
If you have high blood pressure (hypertension) and low levels of potassium, your doctor may recommend that you have a renin and aldosterone test.
After checking your renin and aldosterone levels, your doctor will be able to recommend the most appropriate medication for your high blood pressure.