With the development of society, people’s living standards are gradually improving, which can be reflected in their dietary conditions. In addition, medical science is also developing, and many diseases are gradually being recognized, such as diabetes. When it comes to diabetes, I believe that most people are not unfamiliar with it, and the age of onset is getting younger and younger. In fact, with active prevention and screening, early detection and treatment of diabetes can be achieved and controlled early. So, what are the tests for diabetes? Diabetes is not an exact disease, but a group of clinical metabolic syndrome. As the disease develops, it can gradually accumulate in all major organs of the patient’s body, leading to dysfunction in all aspects of the body and seriously affecting the patient’s quality of life. For diabetes, four tests are essential: blood glucose test, beta cell function measurement, glycosylated hemoglobin test and urine glucose test. The elevation of blood glucose is an important basis for the diagnosis of diabetes, mainly including fasting blood glucose and 2-hour postprandial blood glucose. If fasting blood glucose is ≥7.0 mmol/L (126 mg/dL) and/or 2-hour postprandial blood glucose is ≥11.1 mmol/L (200 mg/dL), then this can be a diagnosis of diabetes in the patient. In addition to blood glucose, it is also extremely important to measure insulin and C-peptide levels at each time phase by beta-cell function assay, because in children with type I diabetes, blood glucose summits are significantly higher during glycemic load and do not return to baseline levels at 2h, while insulin and C-peptide responses are low, thus helping the physician to diagnose whether the patient has diabetes. In addition, glycosylated hemoglobin and urine glucose tests can also be useful in confirming the diagnosis and should be taken seriously. For patients diagnosed with diabetes, the first thing to do is to provide early education to the patient, because most patients are not aware of the various precautions for the disease, and to control the disease well requires the patient to maintain a good diet and lifestyle habits. Therefore, early education must be done after diagnosis, which is the most crucial step in the diagnosis and treatment of type 1 diabetes.