Hyperkalemia, with blood potassium levels greater than 5.5 mmol/L, commonly occurs due to decreased potassium excretion or abnormal potassium transport within cells, as well as other reasons such as excessive intake. Decreased potassium excretion can commonly be due to renal failure, the use of potassium-sparing diuretics, renal tubular acidosis, and reduced secretion of corticosteroid aldosterone. Abnormal potassium transport includes conditions such as acidosis, rhabdomyolysis, extensive burns, severe trauma, intestinal necrosis, and peritoneal bleeding, among other diseases. Excessive potassium intake can be due to sample hemolysis or an elevation in white blood cells, both of which can lead to hyperkalemia. Therefore, it is crucial to be vigilant in clinical settings and address the condition promptly and appropriately.