Sleeping up the back of the neck pain can be caused by pillow fall, neck muscle spasm, cervical spondylosis and other reasons. 1. Falling pillow: it is a disease characterized by stiffness, pain and limitation of movement of the neck muscles in the morning. It may be caused by incorrect sleeping posture, high pillow and so on, which may appear the phenomenon of pain behind the neck after a sleep. 2. Neck muscle spasm: caused by excessive exercise, cold and other reasons, stimulate the muscles behind the neck spasm. Neck pain, limitation of limb movement and other symptoms can occur, which in turn causes the phenomenon of pain in the back of the neck after sleeping. 3. Cervical spondylosis: due to chronic injury, degenerative diseases and other reasons, the lesion site of the stimulation of the local nerve root, can appear after sleeping up neck pain, dizziness and other symptoms. The pain in the back of the neck after sleeping may also be caused by other reasons, such as cervical myofasciitis, etc. It is recommended to go to the hospital in a timely manner, do the relevant examinations, and clarify the cause of the disease under the guidance of the doctor for treatment.