Potassium chloride is a potassium supplement, whether it is a potassium chloride tablet, an extended-release tablet, an oral solution, or a potassium chloride injection, all serve the same purpose: to replenish potassium in patients with hypokalemia or to prevent them from developing hypokalemia. Clinically, some patients may develop hypokalemia for various reasons, such as vomiting, severe diarrhea, inadequate feeding, use of potassium-depleting diuretics, long-term use of glucocorticoids, hypokalemic periodic paralysis, and supplementation with hypertonic glucose solutions, etc., all of which can be treated by oral or infusion of potassium chloride. Patients who are at high risk of hypokalemia, especially if they are suffering from hypokalemia, such as patients on cardiac drugs like digitalis, patients with little food, chronic or severe diarrhea, patients on long-term adrenocorticotropic hormones, etc., can also be treated with oral or infusion potassium chloride to prevent hypokalemia. In addition, potassium chloride can be used to treat tachyarrhythmias caused by cardiac drug digitalis toxicity, as well as frequent and multiple premature beats.