Left foot surface fever is usually seen in the following two conditions, the most common is due to the local inflammatory reaction of the nerve on the back of the left foot, usually manifested as burning pain or radiating pain in the foot surface area, combined with numbness of the skin, usually seen in the inflammatory reaction of the nerve endings. For this condition, the main symptomatic treatment is to nourish the nerve and other drugs, can be combined with local acupuncture, moxibustion, can also be more foot soak or hot compress treatment to improve local blood circulation, to promote nerve recovery. The second cause may be lumbar disc herniation, usually seen in the lumbar 4, 5 disc herniation, compression of the lumbar 5 nerve root, resulting in the lumbar 5 nerve root innervation area muscle numbness or skin sensation, mainly concentrated in the outer calf, dorsal foot and other areas of skin sensation or burning pain. In this case, we should actively improve the lumbar spine CT or MRI examination, and then choose the appropriate treatment plan according to the situation.