If the left foot alone is numb, the following possibilities should be considered: first, peripheral neuropathy, peroneal nerve palsy, diabetic peripheral neuropathy caused by the left foot numbness, can be treated with oral vitamin B1, methylcobalamin tablets nerve nutrition. Second, the left foot artery stenosis, poor blood circulation caused by numbness, oral treatment to improve the circulation of drugs. Third, numbness in the left foot caused by lumbar spine lesions compressing nerves. If the symptoms are not too heavy, local physiotherapy can be performed, and the symptoms may be improved. If it is caused by serious lumbar spine lesions compressing nerves, consider surgery for radical treatment. It is recommended to go to the neurology department of the hospital and perform electromyography, lumbar spine MRI and lower extremity arteriovenous ultrasound to clarify the cause.