When hypokalemia occurs in the human body, it produces characteristic manifestations on the electrocardiogram (ECG) known as U waves. These so-called U waves appear as small waves at the tail end of the ST-T segment, often accompanied by a slight depression of the ST-T segment and mild changes in the T wave. If hypokalemia is severe, it can induce supraventricular arrhythmias, including premature ventricular contractions or first-degree atrioventricular block. In very severe cases, it may lead to life-threatening torsades de pointes, a type of ventricular tachycardia. Therefore, monitoring blood potassium levels and timely potassium supplementation are crucial for these patients to protect their health and safety.