Often sleeping in the middle of the night to find numbness in the left hand, may be in the sleep of the left hand of the nerve compression, such as the brachial plexus nerve compression, the median nerve compression or carpal tunnel syndrome, may cause the left hand numbness. The patient has cervical spondylosis, due to the sleeping posture caused by the cervical spine on the nerve compression symptoms worsened, nerve edema, may also appear left hand numbness. So this situation can change the sleeping position, go to the hospital to check the cervical spine, if it is caused by cervical spondylosis, according to the patient’s specific situation to decide whether the drug treatment, or surgical treatment.