Fasting blood glucose test, oral glucose tolerance test 2-hour blood glucose test and glycosylated hemoglobin can be done to suspect diabetes. Diabetes mellitus is a cluster of metabolic disorders characterized by a chronic increase in blood glucose levels, and patients may experience typical symptoms such as excessive drinking, excessive eating, excessive urination, and weight loss. If these symptoms are present, the possibility of having diabetes exists. Patients should have a blood glucose test, a 2-hour oral glucose tolerance test blood glucose test, and a glycated hemoglobin test, etc. A diagnosis can be made if fasting blood glucose is ≥7 mmol/L or 2-hour oral glucose tolerance test blood glucose is ≥11.1 mmol/L or glycated hemoglobin is ≥6.5%. If you suspect that you have diabetes, you should go to the local hospital for relevant examinations and timely diagnosis and treatment.