Intravenous potassium supplementation is a common clinical treatment for hypokalemia, but the concentration of intravenous potassium supplementation should not exceed 0.3 mmol/L. If the concentration of intravenous potassium is too high or if the blood flow is too fast, the patient may experience hyperkalemia, which may cause cardiac arrhythmia or even cardiac arrest. Therefore, the concentration of intravenous potassium should not be too high and the speed should not be too fast. The most common clinical causes of hypokalemia are: first, patients with poor dietary function, such as patients with gastrointestinal disorders or chronic diarrhea; second, patients who use potassium-depleting diuretics, which are prone to hypokalemia, especially in elderly patients, who experience weakness in the limbs, panic, chest tightness, and in severe cases, nausea, vomiting, and limb weakness. In severe cases, nausea, vomiting and limb weakness may occur. If oral potassium supplementation is available, it should be given first. If oral potassium supplementation is not effective, intravenous potassium supplementation is needed.