Laboratory findings consistent with the diagnosis of hypoaldosteronism include hyperkalemia and mild non-anion gap metabolic acidosis. Other lab findings include hyponatremia, decreased aldosterone level, and variable amounts of plasma renin activity (depends upon the underlying condition).

• Laboratory findings consistent with the diagnosis of hypoaldosteronism include:^[1][2]
  • Hyperkalemia
  • Mild non-anion gap metabolic acidosis

• Laboratory investigations to be performed in hypoaldosteronism includes:^[3]
  • Serum potassium: Hypoaldosteronism patients have hyperkalemia and should be categorised into mild hyperkalemia (5.5–6.5 mmol/l), moderate hyperkalemia (6.5–7.5 mmol/l) and severe hyperkalemia (>7.5 mmol/l).
  • Serum sodium: In general, hyponatremia is unusual in hypoaldosteronism but if the cause of hypoaldosteronism is adrenal insufficiency, hyponatremia may be present. Hyponatremia must be categorized into mild hyponatremia (130-134 mmol/L), moderate hyponatremia (125-129 mmol/L) and severe hyponatremia(<125 mmol/L).
  • Patients suspects of hypoaldosteronism should be checked for plasma renin activity (PRA), serum aldosterone, and serum cortisol.
  • The following table distinguishes among various subtypes of hypoaldosteronism:^[4][5][6][7]