Description
The Renin Activity (PRA) Blood Test measures the activity of renin, an enzyme produced by the kidneys that plays a critical role in regulating blood pressure, fluid balance, and electrolyte levels. This test helps diagnose conditions such as hypertension, primary aldosteronism, and other disorders of the renin-angiotensin-aldosterone system (RAAS).
It is often ordered when patients have high blood pressure that is difficult to control, unexplained low potassium levels, or suspected adrenal gland dysfunction.
Purpose of the Test
- Evaluate causes of high or low blood pressure
- Detect primary hyperaldosteronism or other adrenal disorders
- Monitor patients with kidney or heart conditions affecting fluid and electrolyte balance
- Aid in the diagnosis of secondary hypertension
- Guide treatment decisions for antihypertensive therapy
Who Should Consider This Test?
- Individuals with resistant hypertension
- Patients with low potassium (hypokalemia) of unknown cause
- Those with suspected adrenal gland disorders
- Individuals undergoing evaluation for kidney or cardiovascular disease
- Patients on certain medications affecting RAAS (may require temporary adjustment before testing)
What the Test Measures
- Plasma Renin Activity (PRA):
- Measures the enzyme’s activity in converting angiotensinogen to angiotensin I, which helps regulate blood pressure and fluid balance.
Abnormal PRA levels can indicate overactive or underactive renin systems, guiding diagnosis and therapy for blood pressure and kidney-related disorders.
Fasting Required?
Fasting is not required.
