Diabetic dry lips may be related to the disease itself causing abnormal metabolism and elevated blood glucose, or it may be caused by complications such as diabetic ketoacidosis. Specific causes need to be analyzed and judged by a professional physician through the examination results. Diabetes mellitus is a common clinical metabolic disease, with chronic hyperglycemia as the main feature of the disease. When the body continues to be in a state of elevated blood glucose, it will increase the patient’s urinary output through the effect of osmotic diuresis, and then the symptoms of excessive drinking and dry mouth will occur. In addition to this, if diabetes is complicated by diabetic ketoacidosis, the symptoms of thirst and dry lips will also occur, and typical symptoms such as nausea, vomiting, and the smell of rotten apples on the exhaled breath may also occur. If the symptoms of dry lips persist in diabetic patients, it is necessary to consult a medical professional for diagnosis and treatment if necessary to avoid delaying the condition.