Typical diabetes mellitus manifests itself as three excesses and one deficiency, i.e., excessive drinking, excessive urination, excessive eating and weight loss. Many patients have obvious thirst and weakness, and the weakness can be relieved when the blood sugar is corrected to normal. There are also some patients who do not have obvious symptoms and have high blood sugar detected during routine physical examination. In addition, some patients may be found to have high blood glucose when they visit other departments for certain symptoms, such as itchy skin, female vulva itching or recurrent urinary tract infections, periodontitis, blurred vision, numbness in fingers, and increased foam in urine. A few patients start with coma can be seen in, for example, type 1 diabetic patients after eating a lot of sweets without insulin treatment, or elderly diabetic patients who become dehydrated in hot conditions and develop hyperglycemic hyperosmolar coma. When you have the above symptoms, you need to take fasting and two-hour postprandial blood glucose tests in time to facilitate early diagnosis and treatment, delay the occurrence of complications and improve the quality of life!