Symptoms of Hypoaldosteronism
Hypoaldosteronism primarily presents with electrolyte abnormalities including hyperkalemia, hyponatremia, and metabolic acidosis, along with symptoms of volume depletion such as fatigue, muscle weakness, postural dizziness, and hypotension. 1
Clinical Manifestations
Primary Symptoms
- Electrolyte Abnormalities:
Common Clinical Presentations
- Fatigue and exercise intolerance
- Muscle weakness and cramps
- Postural dizziness
- Low blood pressure or orthostatic hypotension
- Weight loss
- Increased heart rate
- Abdominal pain
- Low urine volume
- Lethargy and confusion 2
Laboratory Findings
- Elevated serum potassium (typically >5.0 mmol/L)
- Decreased serum sodium (typically <135 mmol/L)
- Decreased serum bicarbonate (metabolic acidosis)
- Elevated serum creatinine (prerenal renal failure)
- Increased plasma renin activity (in most forms of hypoaldosteronism)
- Low or inappropriately normal aldosterone levels 2, 1
Types of Hypoaldosteronism
Isolated Hypoaldosteronism
- Most common form in adults (95% of cases) 1
- Often associated with hyporeninemic hypoaldosteronism
- Frequently seen in older patients (>50 years)
- Common in patients with diabetes mellitus and/or nephropathy 3
Primary Adrenal Insufficiency
- Hypoaldosteronism as part of broader adrenal insufficiency
- Additional symptoms related to cortisol deficiency
- Less common (only 5% of hypoaldosteronism cases) 1
Pseudohypoaldosteronism
- Presents with similar electrolyte abnormalities but due to resistance to aldosterone action
- Type I: characterized by insensitivity of the distal nephron to aldosterone
- Type II: associated with hyperabsorption of chloride in the distal nephron and hypertension 4
Risk Factors and Associated Conditions
- Advanced age (median age 77 years in one study) 1
- Diabetes mellitus
- Chronic kidney disease
- Interstitial nephropathy
- Hydronephrosis
- Use of certain medications:
Diagnostic Considerations
- Hyperkalemia may be the only presenting abnormality in some patients
- Normal potassium levels do not rule out primary aldosteronism (the opposite condition) 5
- In infants, high aldosterone levels may paradoxically be seen in early aldosterone deficiency, mimicking pseudohypoaldosteronism 6
- The ratio of stimulated plasma aldosterone to serum potassium can help differentiate hypoaldosteronism (ratio <3) from normal aldosterone function 7
Complications
If left untreated, hypoaldosteronism can lead to:
- Severe hyperkalemia causing cardiac arrhythmias
- Worsening renal function
- Metabolic acidosis
- Hypovolemic shock in severe cases
- Impaired cognitive function 2
Early recognition of these symptoms is crucial for prompt diagnosis and treatment to prevent life-threatening complications, particularly in older patients and those with underlying renal disease or diabetes.