High Aldosterone Symptoms: What Could Be Causing It?

What Does Aldosterone Actually Do in the Body?

Aldosterone is a mineralocorticoid hormone secreted by the adrenal glands that tells the kidneys to hold on to sodium and excrete potassium. When levels are chronically high, this process runs in overdrive, raising blood volume, blood pressure, and cellular potassium loss simultaneously. Understanding the mechanism matters because it explains every symptom on this list.

The Renin-Angiotensin-Aldosterone Axis

The renin-angiotensin-aldosterone system (RAAS) is the principal regulator of aldosterone output. Renin, released by the kidneys in response to low perfusion pressure or low sodium delivery, converts angiotensinogen to angiotensin I, which angiotensin-converting enzyme (ACE) then converts to angiotensin II. Angiotensin II stimulates the adrenal zona glomerulosa to release aldosterone [1].

In primary hyperaldosteronism, this control loop is bypassed entirely. The adrenal gland secretes aldosterone autonomously, so renin is suppressed rather than elevated. In secondary hyperaldosteronism, the kidneys correctly sense low perfusion or low sodium and appropriately raise renin, but the downstream aldosterone surge causes the same symptoms.

Why Potassium Loss Drives the Symptom Cluster

Aldosterone opens epithelial sodium channels (ENaC) in the collecting duct. Sodium enters the cell, and potassium exits into the tubular lumen via ROMK channels. Each extra unit of aldosterone activity accelerates this exchange. Potassium falls below the 3.5 mEq/L reference range in roughly 37% of patients with confirmed primary aldosteronism, though nearly all patients show relative hypokalemia once dietary potassium is controlled [2]. That cellular potassium depletion directly causes muscle weakness, cardiac arrhythmia risk, and polyuria.

Recognizing the Symptoms of High Aldosterone

Most patients with excess aldosterone do not present with a dramatic single complaint. They arrive at a primary care office with blood pressure that will not respond to two or three antihypertensives, and the aldosterone excess is discovered only after a systematic workup.

Resistant Hypertension

Hypertension that fails to reach target despite three optimally dosed agents, including a diuretic, meets the standard definition of resistant hypertension set by the 2018 ACC/AHA Hypertension Guidelines [3]. Primary aldosteronism is one of the most common identifiable causes of this pattern. In a prospective cohort of 1,616 patients referred to a German hypertension center, 21.6% had biochemically confirmed primary aldosteronism [4].

Blood pressure from aldosterone excess tends to be systolic-dominant, often exceeding 160 mmHg systolic, and shows only modest nocturnal dipping on ambulatory blood pressure monitoring. This "non-dipping" pattern is itself a cardiovascular risk factor.

Hypokalemia and Its Downstream Effects

Low serum potassium is the symptom bridge that connects the hormone abnormality to the physical complaints a patient describes. Common presentations include:

• Muscle cramps or persistent weakness, particularly in the legs
• Palpitations or an irregular heartbeat (atrial fibrillation occurs 3.5-fold more often in primary aldosteronism than in matched essential hypertensive controls) [5]
• Constipation, because smooth muscle is potassium-dependent
• Excessive thirst (polydipsia) driven by the kidney's impaired concentrating ability

Polyuria and Nocturia

Chronic hypokalemia induces nephrogenic diabetes insipidus: the collecting duct becomes resistant to antidiuretic hormone (ADH), causing large volumes of dilute urine. Patients commonly report waking two to four times per night to urinate, often months or years before hypertension is diagnosed. A prospective study of 204 patients with confirmed primary aldosteronism published in the Journal of Clinical Endocrinology and Metabolism found that 72% reported nocturia as a presenting complaint [6].

Fatigue and Cognitive Slowing

Hypokalemia reduces membrane excitability across skeletal and cardiac muscle as well as neurons. Patients often describe a fatigue that is different from tiredness after exertion, more like a heaviness or difficulty initiating movement. Some describe mild difficulty concentrating. These symptoms are non-specific and frequently attributed to stress or poor sleep before the correct diagnosis is made.

Headache

Chronic blood pressure elevation itself produces occipital headache, particularly on waking. The pressure is highest in the early morning in aldosterone-excess states because aldosterone secretion follows a circadian peak aligned with the cortisol axis.

What Causes High Aldosterone? Primary vs. Secondary Hyperaldosteronism

The single most important diagnostic distinction is whether the aldosterone excess originates inside the adrenal gland (primary) or is driven by signals arriving at the adrenal gland from elsewhere (secondary). The treatment paths diverge completely depending on that answer.

Primary Hyperaldosteronism (Conn Syndrome)

Primary hyperaldosteronism (PA) means the adrenal gland is producing aldosterone independently of RAAS stimulation. Renin is suppressed as a result.

Aldosterone-producing adenoma (APA). A benign unilateral adrenal tumor secreting aldosterone accounts for approximately 30-35% of PA cases [7]. These tumors are typically small (0.5-2 cm) and are often missed on CT imaging when below 1 cm. Adrenal vein sampling (AVS) is required to confirm lateralization before surgery. Cure rates after unilateral adrenalectomy reach 30-72% for hypertension resolution and approach 100% for hypokalemia correction [8].

Bilateral adrenal hyperplasia (BAH). Bilateral nodular or diffuse hyperplasia of the zona glomerulosa accounts for the remaining 60-65% of PA cases and is not surgically correctable. Medical management with a mineralocorticoid receptor antagonist (MRA) is the standard approach.

Glucocorticoid-remediable aldosteronism (GRA). A rare autosomal dominant condition caused by a chimeric gene fusing CYP11B1 and CYP11B2, GRA puts aldosterone production under ACTH control. Aldosterone normalizes with low-dose dexamethasone 0.125-0.25 mg/day. The Endocrine Society recommends genetic testing for GRA in patients with PA and a family history of early-onset hypertension or stroke [9].

Adrenocortical carcinoma (ACC). Rare (<1% of PA), but aldosterone-secreting ACC should be suspected when an adrenal mass exceeds 4 cm, has irregular borders, or has a CT density above 10 Hounsfield units on non-contrast imaging.

Secondary Hyperaldosteronism

Secondary hyperaldosteronism (SHA) means the adrenal gland is responding normally to an abnormally high renin signal. Renin is elevated rather than suppressed, which is the biochemical distinction from PA.

Renal artery stenosis. Atherosclerotic or fibromuscular dysplasia narrowing of one or both renal arteries reduces renal perfusion pressure, triggering maximal renin release. Renovascular hypertension is classically a young woman with fibromuscular dysplasia or an older man with atherosclerosis. A renal artery bruit on auscultation and asymmetric kidney size on ultrasound are screening clues [10].

Heart failure and cirrhosis. Low effective arterial blood volume in both conditions activates RAAS even though total body sodium is often elevated. Aldosterone rises to retain more sodium, worsening edema and ascites. Loop diuretics in this setting can further raise renin and aldosterone.

Diuretic overuse. Thiazide and loop diuretics lower intravascular volume and sodium delivery to the macula densa, raising renin and then aldosterone. Patients on chronic diuretics may have secondary hyperaldosteronism as an iatrogenic condition. Potassium-sparing diuretics or MRAs can offset this.

Renovascular and parenchymal kidney disease. Chronic kidney disease reduces nephron mass and renin regulation, often driving secondary aldosteronism. Diabetic nephropathy and IgA nephropathy are common culprits.

Bartter and Gitelman syndromes. These rare hereditary tubular disorders mimic chronic loop diuretic use biochemically, with hypokalemia, metabolic alkalosis, and high renin/aldosterone. Blood pressure is typically normal or low, distinguishing them from PA.

How Clinicians Diagnose High Aldosterone

The diagnostic pathway for suspected hyperaldosteronism is a stepwise process. Jumping to advanced imaging before confirming biochemistry is one of the most common errors, because small APAs are frequently missed on CT.

Step 1: Screening with the Aldosterone-to-Renin Ratio

The plasma aldosterone concentration (PAC) to plasma renin activity (PRA) ratio is the first-line screening test. The Endocrine Society 2016 Clinical Practice Guideline sets a positive screen at a ratio above 30 when PAC exceeds 15 ng/dL [9]. Blood should be drawn mid-morning after the patient has been ambulatory for at least 2 hours. Several antihypertensive agents affect the ratio:

• Beta-blockers and central alpha-agonists falsely raise the ratio (suppress renin).
• ACE inhibitors, ARBs, and dihydropyridine calcium channel blockers falsely lower the ratio (raise renin).
• Spironolactone and eplerenone must be stopped for at least 4 weeks before testing.

When medication changes are unsafe, verapamil SR plus doxazosin is a preferred blood pressure bridge regimen during washout [9].

Step 2: Confirmatory Testing

A positive screen requires biochemical confirmation with one of four protocols recognized by the Endocrine Society [9]:

• Saline infusion test: 2 liters of normal saline IV over 4 hours. Post-infusion PAC above 10 ng/dL confirms autonomous secretion.
• Fludrocortisone suppression test (FST): Fludrocortisone 0.1 mg four times daily for 4 days. Day 4 upright PAC above 6 ng/dL is positive. This is considered the most sensitive confirmatory test.
• Oral sodium loading test: 5,000 mg/day sodium diet for 3 days with 24-hour urine aldosterone above 12 mcg/day on day 3.
• Captopril challenge test: PAC reduction <30% after 50 mg captopril is a positive result.

Step 3: Subtype Differentiation

Once biochemistry confirms PA, imaging and adrenal vein sampling (AVS) determine whether the source is unilateral (potentially curable) or bilateral (managed medically).

CT adrenal protocol (thin-slice, 2.5 mm cuts) identifies macroadenomas but misses 25-40% of microadenomas. For this reason, the Endocrine Society recommends AVS in all patients with confirmed PA who are surgical candidates, regardless of CT findings [9]. AVS lateralization index above 4:1 confirms unilateral disease. The procedure should be performed at centers doing at least 20 AVS procedures per year to ensure technical adequacy.

Cardiovascular Consequences of Untreated Aldosterone Excess

Excess aldosterone damages the cardiovascular system through mechanisms beyond blood pressure elevation alone, including direct myocardial fibrosis, endothelial dysfunction, and inflammation.

Cardiac and Vascular Damage

The PAPY Study (Primary Aldosteronism Prevalence in hYpertensives) of 1,125 hypertensive patients found that those with PA had significantly higher rates of left ventricular hypertrophy, stroke, atrial fibrillation, and myocardial infarction compared to matched essential hypertensive controls, even after adjusting for blood pressure levels [5]. The absolute risk difference for atrial fibrillation was 3.5-fold.

Aldosterone receptors exist in cardiac fibroblasts. Chronic activation drives collagen deposition and myocardial fibrosis, increasing QT prolongation risk and diastolic dysfunction. These structural changes may not fully reverse even after aldosterone normalization, making early diagnosis medically significant.

Metabolic Effects

Aldosterone excess reduces insulin sensitivity, partly through potassium depletion (hypokalemia impairs pancreatic beta-cell insulin release) and partly through direct mineralocorticoid receptor signaling in adipose and muscle tissue. A meta-analysis of 22 studies found that the prevalence of metabolic syndrome was 41% in PA vs. 29% in essential hypertension (P<0.001) [11].

Treatment Options for High Aldosterone

Treatment depends on whether the cause is unilateral (surgical) or bilateral (medical), and whether the underlying driver is primary or secondary.

Surgical Treatment: Laparoscopic Adrenalectomy

For confirmed unilateral APA or unilateral adrenal hyperplasia, laparoscopic unilateral adrenalectomy is the treatment of choice. Post-operatively, hypokalemia resolves in nearly 100% of patients within days. Blood pressure normalizes in 30-72% of patients at 6 months, with an additional 20-30% showing significant improvement that still requires fewer medications [8].

Predictors of complete blood pressure cure after surgery include younger age, female sex, fewer years of hypertension, no family history of hypertension, and a lower aldosterone-to-renin ratio preoperatively. The PASO (Outcomes of adrenal surgery for primary aldosteronism) prospective cohort study of 705 patients across 12 centers provides the most granular surgical outcome data available [8].

Medical Treatment: Mineralocorticoid Receptor Antagonists

For bilateral disease or patients who are not surgical candidates, mineralocorticoid receptor antagonists (MRAs) are the cornerstone of medical therapy.

Spironolactone is the first-line MRA. Dosing typically starts at 12.5-25 mg/day and titrates to 100-400 mg/day based on blood pressure and potassium normalization. Anti-androgenic side effects, including gynecomastia in men (occurs in up to 25% at doses above 100 mg) and menstrual irregularity in women, drive discontinuation in a meaningful subset of patients [9].

Eplerenone is a selective MRA with fewer anti-androgenic effects. It requires twice-daily dosing (50-300 mg/day total) and is roughly 60% as potent as spironolactone per milligram. The trade-off is cost and less evidence base in PA specifically.

Finerenone, a non-steroidal MRA, is approved for diabetic kidney disease (FIDELIO-DKD trial, N=5,734) and has a favorable safety profile, but its role in PA is still under investigation as of mid-2025 [12].

Secondary Hyperaldosteronism: Treat the Cause

In secondary forms, the most effective intervention is correcting the upstream problem. Renal artery stenosis may respond to percutaneous transluminal angioplasty with or without stenting. Heart failure management with optimized neurohormonal blockade (ACE inhibitor or ARB plus a beta-blocker) reduces RAAS activation. Cirrhosis management targets portal hypertension. When the cause cannot be fully corrected, low-dose spironolactone (25-50 mg/day) reduces aldosterone receptor activation in end-organs and has a well-documented mortality benefit in heart failure with reduced ejection fraction: the RALES trial (N=1,663) showed a 30% relative reduction in all-cause mortality [13].

When to Seek Evaluation: A Clinical Decision Framework

Not every patient with slightly elevated blood pressure needs a full hyperaldosteronism workup. The following patient profiles represent clear referral thresholds based on current Endocrine Society and ACC/AHA guidance:

Refer for aldosterone screening if the patient has ANY of the following:

1. Sustained blood pressure above 150/100 mmHg on three separate visits
2. Hypertension resistant to three agents, including a diuretic, at optimal doses
3. Spontaneous or diuretic-provoked hypokalemia (serum K below 3.5 mEq/L)
4. An adrenal incidentaloma found on imaging performed for any reason
5. Family history of early-onset hypertension (<40 years) or stroke (<50 years)
6. First-degree relative with confirmed primary aldosteronism
7. New-onset hypertension in a patient under age 40

Blood pressure alone should not determine the urgency. A 38-year-old with potassium of 3.1 mEq/L and blood pressure of 145/92 mmHg is a higher-priority workup candidate than a 68-year-old with stage 2 hypertension and normal potassium.

Monitoring After Treatment

After either surgical or medical treatment, repeat measurement of PAC, PRA, and serum potassium at 6-8 weeks establishes a new biochemical baseline. For surgical patients, the same panel at 3, 6, and 12 months documents durability of remission. For patients on spironolactone, renal function and potassium require monitoring at 4 weeks, 3 months, and then every 6 months indefinitely, because hyperkalemia is a real risk, particularly in patients with CKD or diabetes. Potassium above 5.5 mEq/L should prompt dose reduction.

Ambulatory blood pressure monitoring (ABPM) at 6 months post-adrenalectomy better captures the full antihypertensive response than single-point office readings and is recommended by the PASO investigators as standard follow-up protocol [8].