Early symptoms of diabetes mellitus in children include the typical “three more and one less”, and some of them may also be characterized by slow onset or ketoacidosis state, etc. Most children with diabetes mellitus have an acute onset. Most children with diabetes mellitus have an acute onset of the disease, and the typical symptoms are excessive drinking, excessive urination, excessive eating and weight loss, i.e. “three more and one less”. The typical symptoms are excessive drinking, excessive urination, excessive eating and weight loss, i.e. “three more and one less”. Enuresis may occur due to increased nocturia, and some older children may also suffer from depression and emaciation. A small number of children may have a slow onset of the disease, mainly manifesting symptoms such as mental dullness, weakness, emaciation, etc. In addition, some children may have a slow onset of the disease. In addition, some children are in ketoacidosis at the time of diagnosis, which is characterized by decreased food intake, nausea, vomiting, abdominal pain, muscle pain and other symptoms. If any of the above symptoms occur, it is recommended to consult a doctor in time to avoid delaying the condition.