High blood glucose will show the common clinical manifestations of diabetes mellitus, and the typical manifestations are “three more and one less”, including drinking more, i.e., drinking more water, urinating more, having a dry mouth, eating more, and losing weight, etc. These are the typical clinical symptoms of diabetes mellitus. Early patients with diabetes do not have typical clinical symptoms and are usually diagnosed with diabetes when high blood glucose is found during physical examinations or visits for other diseases. Some patients may have low blood glucose before meals, manifested as palpitations, panic, sweating and hunger, these symptoms may suggest abnormal glucose metabolism and high blood glucose. In these cases, it is recommended to go to the hospital for professional specialist examination, which can detect diabetes in a timely and early manner and enable effective treatment.