Aldosterone & Renin Ratio (ARR): What Your Result Means

Result guide · Endocrine/Hypertension

Content last reviewed 2026-09-12 · Educational information — not medical advice

Quick answer

The ARR hunts primary hyperaldosteronism — high aldosterone despite suppressed renin — which causes 5–10% of hypertension and up to 20% of resistant cases. Far more common than textbooks claimed; massively underdiagnosed.

What is Aldosterone & Renin Ratio (ARR)?

Renin (kidney) and aldosterone (adrenal) form a pressure/potassium regulatory loop. Primary hyperaldosteronism breaks it: adrenal autonomy secretes aldosterone regardless, suppressing renin. The resulting ratio — aldosterone(ng/dL) ÷ renin — flags autonomy. Confounders abound: every major antihypertensive class distorts one arm or the other.

Typical reference interval: ARR <20–30 generally excludes; >30–40 (with confirmatory testing) supports. Cutoffs vary by renin unit conventions (ng/mL/h vs mU/L) — know your laboratory's scale.. Laboratories differ — the interval printed on YOUR report always governs.

If your Aldosterone & Renin Ratio (ARR) is high

Common reasons Aldosterone & Renin Ratio (ARR) runs above the reference interval:

  • Aldosterone-producing adenoma/bilateral hyperplasia — the confirmation targets
  • False-positive confounders — beta-blockers suppress renin, inflating ARR; potassium depletion suppresses aldosterone spuriously
  • Glucocorticoid-remediable aldosteronism — rare familial form

If your Aldosterone & Renin Ratio (ARR) is low

Common reasons Aldosterone & Renin Ratio (ARR) runs below the reference interval:

  • Low aldosterone WITH high renin — secondary hyperaldosteronism — renal artery stenosis, edema-forming states
  • Hypoaldosteronism — diabetic hyporeninism, ACE-inhibitor effects

Symptoms worth knowing

Hypertension itself (often resistant to multi-drug regimens), hypokalemia's cramps/weakness (only ~30% present with LOW potassium though — normokalemic disease dominates), nocturia, muscle cramps. Young hypertensives (<35) deserve screening REGARDLESS of potassium.

What usually happens next

  1. Prep matters: correct potassium first, review interfering meds (switch to verapamil/hydralazine/alpha-blockers per protocol), sample mid-morning seated
  2. Positive ARR → confirmatory saline infusion or captopril challenge — NEVER act on screening alone
  3. Confirmed primary aldosteronism → adrenal CT ± adrenal venous sampling determines surgery versus medical blockade

Get your Aldosterone & Renin Ratio (ARR) checked

These lab tests measure Aldosterone & Renin Ratio (ARR) directly. Ordering online takes a few minutes and results arrive securely.

Aldosterone/Renin Ratio Test

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Panels that include this value

Aldosterone & Renin Ratio (ARR) appears as one line inside these broader panels — better value than ordering single markers alone:

Potassium Context Essential

Related result guides

Potassium (Serum) guideCortisol guideCreatinine (Serum) guide

Frequently asked questions about Aldosterone & Renin Ratio (ARR) results

My blood pressure pills — can I take them before this test?

Many distort results badly (ACE-i/ARBs RAISE renin, beta-blockers CRUSH it). Protocols typically switch patients to neutral agents 2-4 weeks prior. Coordinate with your clinician — never stop antihypertensives unilaterally.

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