1. Wearing inappropriate shoes and poor foot hygiene care. 2.Past history of foot ulcers. 3.Signs of neuropathy (numbness of the foot, decreased or absent sensation of touch or pain) and ischemic vasculopathy (pain or coldness of the gastrocnemius muscle caused by movement). 4.Signs of neuropathy (hot feet, non-sweaty skin, muscle atrophy, eagle claw-like toes, thickened skin at pressure points, very good pulse and good blood filling) and signs of peripheral vasculopathy (cold feet, shiny thinning skin, loss of pulse and atrophy of subcutaneous tissue). 5, Other chronic complications of diabetes (severe renal failure or kidney transplantation, significant retinopathy). 6.Neurological and vascular lesions are not severe but there are severe foot deformities. 7, personal factors (poor socioeconomic conditions, old age or living alone, refusal of treatment and care; smoking, alcohol abuse, etc.). 8, delayed diagnosis of diabetes. Experts remind diabetics to regularly check the foot abnormalities, especially the plantar ulcers of patients should be diligent review, can be 1 to 3 weeks to review once; foot sensory loss of patients can be reviewed every 3 months. Also take good care of the feet to prevent the occurrence of diabetic foot.