Diabetes mellitus at the age of 30 may be related to genetic and environmental (in vitro) factors, among others. The etiology and pathogenesis of diabetes mellitus are extremely complex, and the etiology of different types of diabetes mellitus varies, and even within the same type there is heterogeneity. 1. Genetic factors: diabetes has a family genetic susceptibility, if the patient’s parents suffer from diabetes, their children are more likely to suffer from diabetes. 2. Dietary factors: prolonged intake of a high-fat diet can inhibit metabolic rate and lead to weight gain, resulting in obesity. Obese people are generally prone to diabetes. 3. Disease factors: If you suffer from pancreatitis, pancreatic tumors and other diseases may make insulin secretion is insufficient, resulting in high blood sugar and cause a series of diabetes. Therefore, there is no absolute relationship between the onset of diabetes and age, and it is related to genetic factors, lifestyle and dietary habits and autoimmune factors. It is recommended to go to the hospital in time when the blood glucose is abnormal, and make a personalized treatment plan under the guidance of the doctor after a clear diagnosis.