For different causes of numbness on the outside of the left leg, the treatment methods are different. If dermatitis, neuritis caused by numbness of the outside of the left leg, the general treatment is under the guidance of the doctor to take be prostaglandin sodium, tiantan Tongluo capsule and other drugs, to improve circulation and blood circulation and eliminate blood stasis, and at the same time you need to take methylcobalamin, vitamin B1, cytrophosphorylcholine sodium capsule and other medications to nutritional nerves. If the numbness is caused by nerve compression due to lumbar intervertebral disc or lumbar spinal stenosis, you need to go to the hospital in time to do the relevant CT examination to clarify the cause of the disease. For mild symptoms, use physical methods such as acupuncture, massage or silver needles to relieve the symptoms of numbness on the outside of the left leg. For more severe numbness, surgery is recommended. The treatment of numbness in the left leg needs to identify the cause of the disease and then choose the corresponding treatment method.