Cervical spondylosis causes numbness in the left hand, which can be treated by the following methods: First, conservative treatment: if the symptoms of intermittent numbness, usually need to consider conservative treatment, comprehensive conservative treatment can often achieve better ideal results, generally including continuous traction of the cervical vertebrae, as well as the intravenous use of glycerol fructose injection, mannitol injection, methylprednisolone injection and so on, which can quickly relieve the symptoms. Second, surgical treatment: for the left hand numbness that is ineffective in conservative treatment, it is necessary to consider surgical treatment. By completely removing the intervertebral disc and enlarging the narrowed intervertebral foramen through surgery, the nerve compression can be lifted, and it can make the clinical symptom of the numbness of the left hand be relieved significantly. After surgery, patients should strengthen the cervical muscle exercise to improve the stability of the cervical spine, which can consolidate the effect of surgical treatment and prevent the recurrence of left hand numbness caused by cervical spondylosis.