Hyperkalemia is a more serious clinical condition in which the blood potassium concentration exceeds 5.5 mmol/L. Patients with hyperkalemia generally present with muscle weakness, drowsiness, fatigue and other neurological symptoms. As the cardiovascular system is affected, patients develop cardiac paralysis and a gradual slowing of the heart rate, which may trigger severe arrhythmias and even progress to ventricular fibrillation, which may eventually cause cardiac arrest, the most serious consequence of hyperkalemia. Patients with hyperkalemia do not have typical clinical manifestations, but if they have renal insufficiency or a history of electrolyte disorders, they need to seek prompt medical attention and be diagnosed through tests.