The reason why low sodium and low potassium cannot be replenished may be due to insufficient intake, excessive loss, medication factors, heart weakness and other reasons. 1. Insufficient intake: when patients have gastrointestinal diseases, excessive dieting, pregnant women, and the elderly who are too weak to eat, insufficient food intake will lead to low sodium and low potassium failure to make up. 2. Excessive loss: excessive loss of electrolytes mainly through gastrointestinal tract, urine and sweat, such as prolonged massive vomiting, diarrhea, gastrointestinal and biliary drainage or fistula, which can lead to excessive electrolyte loss. 3. Weak heart: when suffering from weak heart in the elderly, intravenous supplementation of sodium and potassium need to limit the concentration, when the concentration is a little high when the patient will appear localized pain and other reasons, the limitations of the clinical needs, which leads to low sodium and low potassium to make up for the failure. When patients with low sodium and low potassium can not make up, patients had better consult a doctor in time, clear specific reasons and then follow the doctor’s instructions to deal with the drugs should be taken under the guidance of a physician.