Diabetic foot refers to lower limb infection, ulcer formation and/or deep tissue destruction in diabetic patients due to combined neuropathy and various degrees of peripheral vasculopathy. Clinically, diabetic patients are affected by long-term hyperglycemia, lower limb vascular sclerosis, vessel wall thickening, and decreased elasticity, and blood vessels are prone to thrombosis, and set into plaques, which cause lower limb vascular occlusion and nerve damage at the extremities, resulting in lower limb tissue lesions. Clinical manifestations: Patients mostly have the symptoms and signs of diabetes; or no obvious diabetic manifestations, but there are relevant examinations showing that they have diabetes. In addition, the manifestations in the limbs mainly include limb ischemia, nerve dysfunction and infection. The clinical characteristics are: the onset of the limbs, the lower extremity lesions are heavy, the upper extremity lesions are light; often symmetrical bilateral lower extremity lesions, large blood vessels and microvascular involvement at the same time; slow onset, limb ischemia gradually aggravated, often secondary to infection and become wet gangrene. 1, limb ischemic symptoms and signs: symptoms: early patients often have cold, cold or heat, numbness, pain, aggravated in the cold season or at night. Some patients first appear intermittent claudication, suggesting a larger vascular lesion causing ischemia of the lower limbs. As the lesion progresses, the above symptoms gradually worsen and the intermittent claudication distance becomes shorter. When the lesion develops and the ischemia of the lower extremity is further aggravated, resting pain occurs, mostly in the toes and distal end of the foot, and the pain increases when lying down at rest, especially at night, affecting sleep. When the lower limb drops, the blood flow to the limb increases due to gravity, which can appropriately relieve the pain. Therefore, many patients often sleep in a compulsive sitting position, which leads to secondary edema of the lower limb and further aggravates the condition. Signs: weakening or disappearance of dorsal foot and posterior tibial artery pulsation; signs of skin dystrophy, including dry skin, poor elasticity, reduced skin temperature, pale or purplish red skin, sparse or lost body hair, slow growth of toenails, deformation, brittle crack, hypertrophy, loss of luster, muscle atrophy, etc., and increasingly obvious as the degree of ischemia increases. 2.Peripheral nerve dysfunction: the terminal sensory disorders of the extremities are dominant, with more lower extremities than upper extremities, and symmetrical pain and sensory abnormalities appear. Sensory abnormalities often appear before pain, mostly from the end of the extremities upward, numbness, ant-like, feverish, cold or electric shock-like sensations, and “glove”-like sensory dullness, the so-called “painless foot”. 3, infection: diabetic patients due to the existence of microangiopathy pathological basis for infection provides favorable conditions, mild trauma (including scratches, cracks, extrusion, etc.) can become a pathway for bacterial invasion. Due to weak local defenses and nerve dysfunction, the infection can spread rapidly along the muscle space and produce large amounts of pus and decaying tissue, forming a fascial cavity hypertension syndrome and even infecting the bone to develop into osteomyelitis. In severe cases, the infection can lead to systemic infection. Infection can exacerbate local microangiopathy and cause rapid expansion of gangrene by embolizing small blood vessels in the skin, both of which are mutually beneficial. This is another major factor in the high rate of amputation and mortality of diabetic gangrene. Treatment: Treatment of this disease should be early detection and early treatment. Active and effective control of diabetes, the use of anticoagulation, fibrinolytic and peripheral vasodilatation methods to actively improve blood circulation, control the development of diabetic vascular disease, to prevent the development of gangrene of the limb; reasonable use of antibiotics to prevent and control infection; active treatment of other complications of diabetes. 1.Pharmacological treatment: mainly to prevent and control atherosclerosis, reduce blood viscosity and coagulability, and improve limb blood circulation and microcirculation. The use of lipid-regulating drugs to improve the abnormalities of lipid metabolism in diabetes and prevent atherosclerosis; the use of comprehensive treatment of viscosity reduction, fibrin removal, aggregation removal and thrombolysis can improve the state of blood rheology, promote the establishment of collateral circulation and improve microcirculation, thus reducing limb ischemia and achieving the prevention and treatment of limb gangrene caused by ischemia. 2.Surgical treatment: Various arterial reconstructive surgery is also an effective method to improve the blood circulation of the limb, but the premise is that the lower limb arteries must have good inflow and outflow tracts, otherwise arterial diversion will not be implemented. 3.Endovascular treatment: It is the mainstream treatment method at present. With the introduction of Deep balloon and the improvement of guidewire and catheter material, most of the arterial stenosis and occlusive diseases of the lower extremities below the knee can be solved by endovascular treatment. The arterial stenosis and occlusion can be fully dilated with a slender Deep balloon to improve the blood supply to the limb, which can significantly improve the ischemic state of the limb, significantly relieve the painful symptoms of the limb, and promote the healing of the ulcer and gangrene wound of the limb. Some scholars are trying to place stents in the arteries below the knee joint, and the short-term patency rate is clinically reported to be good. 4.Stem cell transplantation: Stem cells are extracted from bone marrow or peripheral blood and injected into the calf muscle or into the femoral artery, which is clinically reported to significantly improve limb pain symptoms, but the long-term effect is not good. 5.Venous arterialization: The arterial blood is introduced into the vein by “bridging” between the artery and vein of the limb, that is, the superficial or deep vein of the lower limb becomes the “artery” that supplies blood to the limb. The clinical application is decreasing because it can cause more obvious swelling of the limb. In conclusion, the main thing is to prevent diabetic foot and limb vasculopathy. First of all, we should control blood sugar exactly, and then we should pay attention to the protection of the limb, avoiding extrusion, bruises and burns of the limb. Once the skin of the toe or limb is found to be broken and infected, it should be treated immediately at a regular hospital, because the disease develops rapidly and often leads to the rapid expansion and spread of infected necrotic lesions within a few days, leading to the adverse consequences of toe or limb amputation.