Hypokalemia is a relatively common clinical condition that is seen in all departments. Its main symptoms include those that occur when the heart, neuromuscular and digestive systems are involved. Normal blood levels of potassium range from 3.5 to 5.5 mmol/L. A blood potassium level below 3.5 mmol/L is called hypokalemia. For patients with hypokalemia, the symptoms include the following: first, the heart. Patients may have various arrhythmias, such as atrioventricular block, ventricular tachycardia or atrial tachycardia. In severe cases, this may lead to heart failure and ventricular fibrillation. Secondly, hypokalemia may also cause neuromuscular symptoms such as muscle weakness and numbness. If the respiratory muscles are involved, respiratory muscle paralysis may occur, leading to asphyxia. If hypokalemia affects the digestive system, it may cause abdominal pain, diarrhea, etc. In severe cases, it may also cause toxic intestinal paralysis. In a nutshell, the symptoms of hypokalemia are mainly cardiac, neuromuscular and digestive, and may vary from patient to patient.