(1) Age: Most type 1 diabetes develops under the age of 40, and most adolescents and children under the age of 20 have type 1 diabetes, with only a few exceptions; most type 2 diabetes is in middle-aged and older people over the age of 40, and few people over the age of 50 have type 1 diabetes. In short, the younger the age, the more likely it is to be type 1 diabetes; the older the age, the more likely it is to be type 2 diabetes. (2) weight at the onset of the disease: most people who are obviously overweight or obese when diabetes occurs are type 2 diabetics, and the more obvious obesity is, the more likely they are to have type 2 diabetes; type 1 diabetics are mostly normal or low weight before the onset of the disease. Whether type 1 or type 2 diabetes, after the onset of weight can be reduced to varying degrees, while type 1 diabetes often have significant wasting. (3) Clinical symptoms: Type 1 diabetes has obvious clinical symptoms such as polyhydramnios, polyuria, polyphagia, etc., that is, “three more”, while type 2 diabetes often does not have the typical “three more” symptoms. A number of type 2 diabetic patients due to clinical symptoms are not obvious, often difficult to determine when the onset of the disease, some only in the blood sugar check before they know they have diabetes. type 1 diabetic patients due to clinical symptoms are more prominent, so they can often point out exactly when their disease. (4) acute and chronic complications: Type 1 and type 2 diabetes can occur in a variety of acute and chronic complications, but there are some differences in the types of complications. In terms of acute complications, type 1 diabetes is prone to ketoacidosis, while type 2 diabetes is less prone to ketoacidosis, but older individuals are prone to non-ketotic hyperosmolar coma. In terms of chronic complications, type 1 diabetes is prone to fundus retinopathy, nephropathy and neuropathy, while atherosclerotic lesions of the heart, brain, kidney or limb vessels are rare, while type 2 diabetes can occur in addition to the same fundus retinopathy, nephropathy and neuropathy as type 1 diabetes, the incidence of atherosclerotic lesions of the heart, brain and kidney vessels is higher, and combined hypertension is also very common. Therefore, type 2 diabetic patients with coronary heart disease and cerebrovascular accident chance far more than type 1 diabetic patients, which is a very obvious difference. (5) Clinical treatment: Type 1 diabetes can only be controlled by injecting insulin to stabilize hyperglycemia, oral hypoglycemic drugs are generally ineffective. type 2 diabetes can obtain certain results through reasonable dietary control and appropriate oral hypoglycemic drug therapy, of course, when oral hypoglycemic drug therapy fails, islet B-cell function tends to fail or serious acute and chronic complications, is also an indication for insulin. (6) Various immune antibody tests: such as GAD antibodies, ICA antibodies, etc. These antibody tests can understand whether the patient’s diabetes is related to immunity.