If you sleep with numbness in your left hand and wake up, it may be caused by left upper limb compression, nerve entrapment syndrome and cervical spondylosis. You can try to adjust yourself first, if you can’t relieve, it is recommended to seek medical attention in time to clarify the specific reasons, according to different reasons for targeted treatment. 1, left upper limb pressure: due to improper posture when sleeping, the left upper limb is pressed under the body, causing local vascular compression, the distal limb blood supply is reduced, there will be symptoms of left hand numbness, wake up when the left upper limb pressure is lifted, blood supply is restored, the symptoms will improve. It is recommended to change the bad sleeping habits, try to sleep flat to avoid pressure on the left upper limb; 2, nerve entrapment syndrome: due to improper sleeping posture, the nerve at the elbow or wrist is entrapped, which can cause local nerve ischemia and edema, and then cause numbness in the left hand, after waking up, the posture changes, the entrapment is lifted, and the symptoms will improve. It is recommended that patients change their bad sleeping posture and take nerve-nourishing drugs for treatment, such as methylcobalamin and vitamin B12; 3. Cervical spondylosis: patients have cervical spondylosis, and improper neck posture during sleep can lead to cervical spondylosis attacks, so that the nerves in the spinal cord are compressed, which can cause numbness in the left hand when sleeping. Patients are advised to sleep as flat as possible, and cervical spine traction treatment can be combined with acupuncture treatment. If painful symptoms occur in cervical spondylosis, it is recommended to follow medical advice to use pain medication, such as celecoxib capsules, ibuprofen, etc.