At present, diabetes is prevalent in China, and there is a trend of youthfulness. Therefore, it is necessary to acquire some general knowledge to determine the disease, so that early detection, early detection and early control can be achieved. The onset of diabetes has precursors. The typical symptoms are “three more and one less”, i.e., excessive urination, excessive drinking, excessive eating and weight loss. In addition to “three more and one less”, the following conditions should be examined and diagnosed in time: 1. 2~3 hours after meals or before lunch and dinner, symptoms such as panic, fatigue, excessive sweating, dizziness, hunger, etc. 2. frequent septic skin infections 3. women of childbearing age with a history of multiple miscarriages, fetal malformations, giant fetuses, excessive amniotic fluid, etc. 4. 4, women with recurrent urinary tract infections and frequent itching of vulva 5, men with impotence 6, unexplained heavy limbs, numbness, calf pain or painful spasms 7, sudden vision loss of unknown origin 8, elderly with unexplained coma, hypertension, coronary heart disease, etc. 9, unexplained extremity necrosis 10, premature arteriosclerosis and hypertension 11, physical weakness, wasting 10, unexplained growth retardation, etc. In daily life, we have to prevent and correct obesity, avoid eating high-fat food. Among them, carbohydrates to non-refined, rich in soluble vitamins is good, accounting for 50% to 65% of total food calories, fat accounts for 15% to 20% of total food calories (the ratio of polyunsaturated fatty acids to saturated fatty acids is greater than 1.5), protein accounts for 10% to 15% of total food calories, and eat more vegetables. You should also increase physical activity and participate in physical exercise; avoid or reduce the use of drugs that are detrimental to sugar metabolism; actively detect and treat hypertension, hyperlipidemia and coronary heart disease; and quit smoking and drinking and other bad habits. People with high risk of diabetes such as obesity or overweight, somewhat high blood pressure and lipids, and family history of diabetes should have their blood glucose measured every 3 years after the age of 30; the general population should have their blood glucose measured every 3 years after the age of 45. This allows for early detection, diagnosis and treatment, and can even prevent people at high risk for diabetes from developing diabetes.