Bruising and purpling on the outside of the diabetic foot may be caused by a bump, diabetic foot, or other conditions, and immediate hospitalization is recommended. If the bruising is caused by diabetic foot, it is recommended to actively control blood sugar to prevent adverse outcomes. Purple bruising on the outside of the diabetic foot may be a clinical manifestation of diabetic foot. The treatment of purple bruising on the outside of the diabetic foot should be evaluated and treated based on whether there is a breakthrough and whether the breakthrough surface is severe. If there is only a small area of bruising and purple should actively control blood glucose, wear loose and comfortable shoes, actively control blood glucose, as well as diabetic foot care education and regular follow-up. Therefore, when diabetic patients have foot symptoms (e.g. foot deformity, abnormal skin temperature, etc.), they should go to the hospital immediately to prevent the occurrence of adverse prognosis.