Symptoms and Signs of Primary Aldosteronism
Primary aldosteronism typically presents with hypertension—often resistant or severe—and is frequently asymptomatic beyond elevated blood pressure, because hypokalemia occurs in only approximately 50% of cases and is a late manifestation of the disease. 1
Key Clinical Presentations
Hypertension Patterns
- Resistant hypertension is the most common presentation, defined as blood pressure remaining >140/90 mmHg despite optimal doses of three or more antihypertensive medications including a diuretic, or requiring four or more drug classes 1, 2
- Severe hypertension (BP >180/110 mmHg) should prompt immediate screening, as prevalence reaches 13% in this population 1
- Early-onset hypertension in patients <30-40 years without traditional risk factors like obesity warrants evaluation 3, 2
- Abrupt onset or worsening of previously well-controlled hypertension is a red flag 2
Electrolyte and Metabolic Manifestations
- Hypokalemia (spontaneous or diuretic-induced) occurs in only ~50% of patients, making it an unreliable screening trigger when absent 1, 4
- Muscle cramps or weakness may accompany hypokalemia when present 1, 2
- Serum potassium levels are rarely low in confirmed cases, as hypokalemia represents a late manifestation preceded by years of hypertension 1, 4
Associated Conditions and Comorbidities
- Obstructive sleep apnea co-occurs frequently with primary aldosteronism 1, 2
- Atrial fibrillation is 12.1-fold more common than in essential hypertension matched for blood pressure level 3, 2
- Incidentally discovered adrenal mass on imaging performed for other reasons 1, 2
Family History Red Flags
- Early-onset hypertension in first-degree relatives 1, 3
- Stroke at young age (<40 years) in family members suggests possible familial hyperaldosteronism 1, 3, 2
Target Organ Damage Disproportionate to Blood Pressure
Primary aldosteronism causes dramatically worse cardiovascular outcomes than essential hypertension at equivalent blood pressure levels 3:
| Cardiovascular Outcome | Relative Risk vs. Essential HTN |
|---|---|
| Heart failure | 3.7-fold increase |
| Stroke | 4.2-fold increase |
| Myocardial infarction | 6.5-fold increase |
| Atrial fibrillation | 12.1-fold increase |
- Left ventricular hypertrophy and diastolic dysfunction exceed what would be expected from blood pressure elevation alone 2
- Increased arterial stiffness and widespread tissue fibrosis develop 2
- Kidney damage progresses more rapidly than in matched primary hypertension 2
Critical Pitfalls to Avoid
- Never rely on presence or absence of hypokalemia alone to screen for primary aldosteronism—normal potassium does not exclude the diagnosis 1, 3, 2
- Do not wait for "classic" symptoms like muscle weakness or polyuria, as most patients lack these features 1
- Recognize that primary aldosteronism is common, affecting 5-10% of all hypertensive patients and up to 20% of those with resistant hypertension—it is not a rare zebra diagnosis 3, 5, 6
- Screen high-risk patients systematically, as only ~2-4% of eligible patients currently undergo testing despite the condition's prevalence 3
When to Screen (High-Risk Populations)
Screen using the aldosterone-to-renin ratio (ARR) in patients with 1, 3, 2:
- Resistant hypertension (most important indicator)
- Spontaneous or diuretic-induced hypokalemia
- Adrenal incidentaloma
- Family history of early-onset hypertension or stroke <40 years
- Severe hypertension (BP >180/110 mmHg)
- Young-onset hypertension (<30-40 years)
- Obstructive sleep apnea with hypertension
The absence of symptoms beyond hypertension should not deter screening in high-risk patients, as early diagnosis and targeted treatment—either unilateral adrenalectomy or mineralocorticoid receptor antagonist therapy—can reverse aldosterone-mediated organ damage and prevent the excess cardiovascular morbidity and mortality associated with this condition. 3, 2, 7