Aldosterone-to-Renin Ratio (ARR) Calculator

Compute the ARR screening ratio to evaluate secondary hypertension and primary aldosteronism (Conn's syndrome).

🔬 Health

Verified Formula

Enter Calculation Inputs

Fill in the fields below. Instant client-side computation runs automatically in your browser as you type.

✓ Computed Output

Computation Ready

Calculation performed instantly via mantranews24 verified mathematical model.

Common Searches & Natural Queries

🔍 aldosterone renin ratio arr calculator 🔍 primary aldosteronism screening calculator 🔍 plasma aldosterone concentration to renin ratio 🔍 hyperaldosteronism arr test calculator 🔍 endocrinology arr ratio

What is the Aldosterone / Renin?

The Aldosterone-Renin Ratio (ARR) is the gold-standard screening index for Primary Aldosteronism (PA), an underdiagnosed cause of treatment-resistant hypertension. Autonomous aldosterone secretion from the adrenal cortex suppresses plasma renin via negative feedback.

Mathematical Formula & Methodology

The mathematical model underlying this tool operates on the following verified equation:

ARR = Plasma Aldosterone Concentration (PAC, ng/dL) / Plasma Renin Activity (PRA, ng/mL/h)

Understanding the Parameters:

Plasma Aldosterone (PAC) (measured in ng/dL) — Primary input variable.
Plasma Renin Activity (PRA) (measured in ng/mL/h) — Primary input variable.

How to Use This Calculator

Input your Plasma Aldosterone Concentration (ng/dL) and Plasma Renin Activity (ng/mL/h). Ensure the units match clinical laboratory report standards.

Worked Numerical Example

💡

PAC = 24.0 ng/dL, PRA = 0.6 ng/mL/h: ARR = 24.0 / 0.6 = 40.0 (ng/dL per ng/mL/h). With an ARR > 20–30 and PAC > 15 ng/dL, this constitutes a positive screen suggesting possible primary aldosteronism.

Key Considerations & Standards

A positive ARR screen (typically ARR ≥ 20 to 30 ng/dL per ng/mL/h with PAC ≥ 15 ng/dL) warrants secondary confirmatory suppression testing (oral sodium loading or saline infusion).

Frequently Asked Questions

What medications interfere with the ARR test?

Mineralocorticoid receptor antagonists (spironolactone, eplerenone) must be discontinued for at least 4–6 weeks. ACE inhibitors and ARBs falsely elevate renin and lower ARR.

What symptoms suggest hyperaldosteronism?

Resistant hypertension requiring three or more antihypertensives, hypokalemia (muscle cramps, weakness), and early-onset hypertension before age 40.