Your Salt and Blood Pressure Regulator
Aldosterone is the hormone that tells your kidneys to hold onto sodium (and water with it) while dumping potassium. This raises blood volume and blood pressure. It's part of the RAAS system (renin-angiotensin-aldosterone)—the body's primary long-term blood pressure control. When aldosterone is too high, you retain too much salt and water.
What is Aldosterone?
Aldosterone is a mineralocorticoid produced by the adrenal cortex zona glomerulosa. It acts on kidney collecting ducts to reabsorb sodium and excrete potassium. Regulated by renin (via angiotensin II), potassium levels, and ACTH. Always interpret with renin (aldosterone:renin ratio is key screening test).
↑ What High Aldosterone Means
Too much sodium retention and potassium loss. Causes resistant hypertension (blood pressure that doesn't respond to medications), low potassium, and metabolic alkalosis. Primary aldosteronism (Conn's syndrome) affects 5-10% of people with hypertension—dramatically underdiagnosed.
Common symptoms:
Resistant hypertension · Low potassium (muscle weakness, cramps, palpitations) · Headaches · Frequent urination · Excessive thirst
↓ What Low Aldosterone Means
Can't retain sodium properly. Causes low blood pressure, dizziness, salt cravings, and high potassium. Part of adrenal insufficiency.
Common symptoms:
Low blood pressure and dizziness · Salt cravings · High potassium · Dehydration · Fatigue
Why It Matters
When normal:
Maintains blood volume and pressure
Regulates sodium-potassium balance
Aldosterone:renin ratio screens for primary aldosteronism
Risks if abnormal:
High: hypertension, hypokalemia, cardiovascular damage, metabolic alkalosis
Primary aldosteronism: 5-10% of hypertensive patients—underdiagnosed
Low: hypotension, hyperkalemia, adrenal insufficiency
What Can Cause Abnormal Levels?
Primary Aldosteronism (high)
45% likelyAdrenal adenoma or bilateral hyperplasia producing excess aldosterone. High aldosterone with suppressed renin.
Secondary Aldosteronism (high)
35% likelyAppropriate aldosterone rise in response to high renin. Caused by heart failure, cirrhosis, renal artery stenosis, or dehydration.
Adrenal Insufficiency (low)
Addison's disease destroys aldosterone-producing cells along with cortisol-producing cells.
Medications
NSAIDs, ACE inhibitors, ARBs, and spironolactone all affect aldosterone/renin.
High Potassium
Potassium directly stimulates aldosterone release (physiological response).
What You Can Do
If resistant hypertension: get aldosterone:renin ratio screened
Impact: Identifies primary aldosteronism in 5-10% of hypertensive patients \u00B7 Timeline: One-time
Moderate sodium intake: 1500-2300mg/day
Impact: Reduces aldosterone drive \u00B7 Timeline: Ongoing
If lifestyle changes aren't enough:
Potassium-rich diet if aldosterone is high (bananas, potatoes, beans)
Impact: Counteracts potassium losses from excess aldosterone \u00B7 Timeline: 1-2 weeks
Stop interfering medications 2-4 weeks before testing (if safe)
Impact: Accurate aldosterone:renin ratio requires medication washout \u00B7 Timeline: 2-4 weeks
Recommended retest: 4-8 weeks after treatment change; confirmatory testing for primary aldosteronism
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