1, the patient’s skin is itchy, dry and sweatless, the extremities are cold, puffy or dry, the skin color is dark and pigmented, and the fine hair is lost. 2, limb malnutrition, muscle atrophy and poor tone, joint ligaments easily damaged. 3, tingling, burning pain, numbness, dullness or loss of sensation in the extremities, and a sense of cotton wool in the feet. Duck walk, intermittent claudication, resting pain. 4.Dorsalis pedis artery pulsation is weakened or disappeared. Depressed or absent deep and superficial reflexes. 5, common metatarsal head subsidence, metatarsophalangeal joint bending to form bowed feet, mallet toe. Chalcone toe, Charcot’s joint. Pathological fractures may occur due to bone destruction. 6. The skin of the extremity is dry and cracked or blistered, blood blistered, eroded, ulcerated, gangrenous or necrotic.