Plasma Renin Activity (PRA)

Why Is This Test Done?

Your doctor may order this test if you have symptoms like high blood pressure, kidney problems, or conditions affecting your kidneys’ ability to regulate fluid and salt, such as certain types of kidney disease or hormonal imbalances. It may also be used to diagnose or monitor conditions like primary aldosteronism or renovascular hypertension.

What Does the Test Involve?

A blood sample is taken from a vein, usually in your arm. The blood is then sent to a lab where it’s processed to measure renin levels in your plasma. This test helps assess kidney function and how well your body’s natural systems are managing blood pressure and fluid balance.

What Are Common Uses?

Plasma renin activity is often used to evaluate kidney function, especially in cases where blood pressure is difficult to control with medication. It can also help identify whether high blood pressure is caused by problems with your kidneys or adrenal glands.

What Might Affect Results?

Several factors can influence renin levels, including medications (like beta-blockers or diuretics), stress, dehydration, or certain medical conditions. If you’re taking medications or have recent changes in health, let your doctor know before the test.