Dry gangrene, mostly a form of gangrene, commonly consists of ischemic necrosis of the tissue at the extremities, which dries and darkens and progresses toward the trunk until the circulation is sufficient to prevent cessation of the necrosis. The lesions of dry gangrene are well-defined. Symptoms of early dry gangrene are whitening of the affected surface and sensation of dull pain and coldness. Localized improvement of circulation is possible at this stage, after which necrotic tissue needs to be removed. However, without treatment, the necrotic part will eventually fall off on its own. Diabetic foot lesions are changes in the foot that are caused by insufficient blood supply due to vascular disease and sensory loss due to neuropathy with infection in diabetic patients. The number of amputations due to diabetic foot lesions is 5-10 times higher than in non-diabetic patients. In fact, similar pathological changes can occur in other parts of the body, but the incidence of foot lesions is significantly higher in patients than in other parts of the body. The main manifestations of the diabetic foot include lower extremity pain, skin ulcers, and from mild to severe can manifest as intermittent claudication, lower extremity rest pain, and foot gangrene. In the early stage of the disease, physical examination can reveal the manifestation of insufficient blood supply to the lower limbs, such as pale skin of the foot when the lower limbs are elevated, and then purplish when the lower limbs are lowered. The foot is cold and the dorsalis pedis artery pulsation is weakened to absent. Intermittent claudication is when the patient sometimes walks and suddenly feels pain in the lower limbs to the point of having to walk with a limp. Rest pain is the result of further development of vascular lesions in the lower extremities, not only is the blood supply to the lower extremities insufficient when walking, but the lower extremities are also painful at rest due to blood loss. In severe cases, patients may have trouble sleeping at night. Further development of the disease, the lower extremities, especially the feet can appear necrosis, wounds do not heal over time, serious cases have to be amputated to disability. Differentiation of foot gangrene from other gangrene: gangrene is the death of tissue cells. Etiology is often divided into circulatory gangrene, such as atherosclerotic gangrene, embolic gangrene, thrombo-occlusive vasculitis, gangrene caused by Raynaud’s disease, neurotrophic gangrene, diabetic gangrene, mechanical, physical, chemical, injury and infectious gangrene. Diabetic foot gangrene is difficult to distinguish from other gangrene by pathological changes and the nature and extent of gangrene alone. It is especially difficult to distinguish between middle-aged and elderly diabetic patients with atherosclerotic gangrene of the arteries. However, patients with diabetic foot gangrene are characterized by severe vascular lesions, rapid progression of lesions, and often associated with peripheral neuropathy and infection. It is also common to encounter clinical cases in which the gangrene of the foot does not heal for a long time and diabetes is detected only during examination. Attention should be paid to analyzing the occurrence of gangrene, whether it is a concomitant disease or a comorbidity, to differentiate it.