Hyponatremia in pediatric patients refers to the fact that children, especially premature babies and newborns, have not yet reached a normal level of renal regulation, water-electrolyte and acid-base balance, and have a poorer ability to regulate. Hyponatremia is more likely to occur when the intake of water is too much or the intake of sodium is too little. Hyponatremia in children is mainly caused by the use of diuretics or low sodium intake during pregnancy, which can cause hyponatremia in premature babies and newborns. Some children are more prone to diarrhea, and if the diarrhea is severe, the gastrointestinal tract will also lose some sodium and lose more, and hyponatremia will also occur. Hyponatremia may also occur as a result of improper medical or artificial feeding, resulting in too much water or too little sodium intake. Clinical signs other than low sodium may occur, such as lower blood pressure, oliguria, and in more severe cases, may cause weakness and muscle tone. More severe cases require rehydration therapy, while milder ones can be corrected by diet.