Diabetes mellitus is a group of metabolic diseases characterized by hyperglycemia. Hyperglycemia, in turn, is caused by defective insulin secretion or impairment of its biological action, or both. The prolonged presence of hyperglycemia in diabetes leads to chronic damage and dysfunction of various tissues, especially the eyes, kidneys, heart, blood vessels, and nerves. Nowadays, diabetes seems to have become one of the most common epidemic diseases in the world, so how can we tell if we are suffering from diabetes, and control and actively treat it in time? Diabetes can cause cataracts, leading to vision loss, and sometimes acute retinopathy, causing acute vision loss. Herpes and itching of the skin. They appear singly or in multiple clusters and heal spontaneously within a few weeks, but can recur repeatedly. Diabetes can cause dry and flaky skin all over the body or locally, and intense itching, often making it difficult to sleep and eat, especially the itching of the female pubic area is more serious. Urinary tract infection Diabetes-induced urinary tract infection has two characteristics: first, bacteriuria originates in the kidney, while general urinary tract infection mostly originates in the lower urinary tract; second, despite appropriate anti-infection treatment, the fever period of acute pyelonephritis is still longer than the fever period of general urinary tract infection. Sweating is abnormal. There is a lot of sweating (mostly in the upper limbs and trunk) or little sweating (mostly in the lower limbs), and some patients even sweat profusely. V. Oral lesions Burning sensation in the mouth, dryness of oral mucosa, redness and swelling of gums, pressure pain, edema of periodontal tissues, formation of periodontal pockets, painful tooth buckling, loosening and loss are seen in typical cases. Due to angiopathy and neuropathy, glucose patients have local microcirculatory damage to periodontal tissues, poor repair ability, sluggish sensation and vulnerability to injury, in addition to low immunity to infection. Due to diabetic bone disease, the alveolar bone is loosened, aggravating periodontal disease, visible as tooth loss and other symptoms. When you have more than three of the above conditions, you must be alert, it is likely that diabetes is coming to you.