Half of the scalp numbness, may be related to physiological factors, may also be due to autonomic dysfunction, cervical spondylosis, cerebral infarction and other causes. 1. Physiological factors: such as sleeping for a long time, half of the head pressure, half of the head cold and other conditions, may cause half of the scalp numbness symptoms, release the pressure and warmth can be relieved on their own. 2. Autonomic dysfunction: usually caused by long-term mental trauma stimulation, emotional instability, or long time living habits, etc., can lead to autonomic dysregulation, may cause half of the scalp numbness, may also be accompanied by panic, insomnia and other manifestations. 3. Cervical spondylosis: the protruding cervical intervertebral discs are easy to compress the local blood vessels and nerve roots, causing insufficient blood supply to the vertebral arteries or compressing the occipital nerves, which may cause numbness of the scalp, and may be accompanied by neck and shoulder pain and numbness of the hands, and other manifestations. 4. Cerebral infarction: due to local ischemia of brain tissue, resulting in damage to the cerebral nerves in the area, inducing cerebral dysfunction, which may result in numbness of the scalp, and may be accompanied by speech disorders, swallowing disorders and other manifestations. Half of the scalp numbness, may also be caused by other reasons, to rule out physiological reasons, it is recommended to consult a doctor as soon as possible, after diagnosing the cause, to give targeted treatment.