Early symptoms of diabetes mellitus are not obvious, and some people may have symptoms such as fatigue, drowsiness, depression, dry and itchy skin, vision changes, sleep disorders, or mild symptoms of “three more and one less”. Self-examination can be done by measuring blood glucose with fingertip blood, including fasting blood glucose and 2-hour postprandial blood glucose. In the early stage of diabetes mellitus, there may be no obvious conscious symptoms, but only non-specific symptoms such as fatigue, drowsiness, depression, dry and itchy skin, changes in vision, sleep disorders, etc. When the disease progresses to a certain degree, the typical “three more and one less” symptoms of excessive drinking, eating, urinating, and weight loss may appear. When type 2 diabetes is diagnosed, diabetic complications may have already occurred, such as diabetic retinopathy and diabetic peripheral neuropathy, which are characterized by blurred vision, itchy skin, slow wound healing, numbness of the hands and feet, and so on. You can use fingertip blood for blood glucose measurement method of self-check to clarify the blood glucose value, mainly including fasting blood glucose and 2-hour postprandial blood glucose. If the blood sugar is abnormal or there are uncomfortable symptoms, you should go to the local hospital to get a clear diagnosis.