Aldosterone and Obesity
Aldosterone is the hormone that makes the kidneys retain sodium and water; excess weight raises aldosterone activity, contributing to high blood pressure and salt and fluid retention.
Plain English
Patient-Friendly Explanation
Aldosterone is made by the adrenal glands and tells the kidneys to hold on to sodium and release potassium, which in turn retains water - it is a major regulator of blood pressure and fluid balance. Fat tissue is not just storage: it produces signals that stimulate aldosterone, and people with excess weight often have higher aldosterone levels than expected even when their renin levels are suppressed. That combination helps explain why high blood pressure in obesity is often salt-sensitive, and why the receptor aldosterone acts on is such an attractive treatment target. In practice it means reducing dietary sodium and choosing blood-pressure medicines that block aldosterone effects can be particularly effective in patients with excess weight.
Medical
Clinical Definition
Obesity is associated with increased aldosterone secretion and enhanced mineralocorticoid receptor signalling, and the relationship is partly renin-independent: adipocytes and adipose-derived factors, including leptin and complement-related peptides, stimulate adrenal aldosterone production, so patients with obesity may show elevated aldosterone with a low or inappropriately normal plasma renin activity, the pattern historically described as low-renin hypertension of obesity. Consequences include sodium and water retention, a salt-sensitive rise in blood pressure, increased left ventricular mass, oxidative stress and inflammation, and insulin resistance - a bidirectional relationship, since aldosterone impairs insulin signalling while hyperinsulinaemia can itself stimulate aldosterone release. This provides the rationale for dietary sodium reduction and for mineralocorticoid receptor antagonists such as spironolactone or eplerenone in resistant or obesity-associated hypertension, with careful potassium and renal monitoring, particularly alongside renin-angiotensin system blockade. A primary adrenal cause (primary aldosteronism) should still be excluded in patients with hypokalaemia, an adrenal incidentaloma or genuinely resistant hypertension, because that diagnosis changes management substantially.
Key Insight
Why It Matters
Two patients can have the same blood pressure reading and respond quite differently to the same medicines. Understanding the aldosterone link explains why salt reduction and a mineralocorticoid-blocking tablet sometimes work unusually well in patients with excess weight - and why we screen for a primary adrenal cause when the picture does not fit.
Sources
Reviewed against standard medical references.
Medically reviewed by
Family Physician & Registered Acupuncturist, Accord Medical Clinic. MBBS (NUS), Graduate Diploma in Family Medicine (NUS), Graduate Diploma in Acupuncture (Singapore College of TCM).
Last reviewed: September 2026
This page is general health education, not medical advice. Whether any treatment is appropriate for you is a decision made in consultation after assessment.
