Aldosterone-Renin Ratio
- Sample Type
- Standard
- Fasting
- No
- Unit
- ratio
The Aldosterone-Renin Ratio (ARR) is the most reliable screening test for Primary Aldosteronism (PA), a condition where the adrenal glands produce too much aldosterone. In a clinical context, aldosterone promotes sodium retention and potassium excretion, while renin is an enzyme that regulates blood pressure. When aldosterone is high and renin is low, the ratio increases, suggesting autonomous aldosterone production that is independent of the renin-angiotensin system. This is a critical screening tool for patients with resistant hypertension or unexplained hypokalemia.
Why Context Matters
The ARR is highly sensitive to external factors. Medications such as beta-blockers, ACE inhibitors, and especially mineralocorticoid receptor antagonists (spironolactone) must be discontinued for weeks before testing. Potassium levels must be normalized, and salt intake must be controlled. Additionally, the patient's posture (upright vs. supine) during the draw significantly impacts results.
Lab ranges are statistical averages, not biological laws. "Normal" for a 20-year-old male isn't normal for a 60-year-old female.
Clinical References
Source-of-truth databases and clinical guidelines for Aldosterone-Renin Ratio:
Official Sources
- Renin Test: MedlinePlus Medical TestMedlinePlus
- Aldosterone and Renin Test - Testing.comTesting.com
- Aldosterone Test: MedlinePlus Medical TestMedlinePlus
Research & Guidelines
- PubMed: Aldosterone-Renin Ratio Clinical GuidelinesNCBI / PubMed
Related Indicators
Medically Reviewed by Dr. Binoy Babu, MBBS
Board Certified Doctor • 10+ Years Clinical Experience
Dr. Babu is a practicing physician dedicated to empowering patients with clear, actionable medical information. He founded 2opi to bridge the gap between complex lab reports and patient understanding, ensuring everyone has access to a reliable second opinion.
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