Clinical numbness of the dorsum of the left foot should be considered for the following reasons: First, lumbar intervertebral disc herniation: when the herniated intervertebral disc tissue compresses the spinal nerve root, radiating pain in the lower limbs and numbness of the foot will occur, especially when the lumbar 4-5 intervertebral disc herniation compresses the lumbar 5 nerve root, which will lead to numbness of the dorsum of the foot. Second, peripheral nerve compression: the dorsum of the foot is mainly innervated by the superficial peroneal nerve, when the superficial peroneal nerve is compressed, numbness and discomfort of the dorsum of the foot will occur. Third, some chronic diseases cause peripheral neuropathy: diabetes can cause peripheral neuropathy in the late stage, which is manifested as numbness of the skin of the hands and feet.