The common causes of abnormal and unusual sensations in the back of the head while sleeping include physiological factors and disease factors, and disease factors include cervical spondylosis, occipital neuralgia, and so on. 1. Physiological factors: when lying down for a long time, the blood circulation in the back of the brain will be blocked, and then there will be local numbness, which is a normal physiological factor and does not require special treatment. 2. Disease factors (1) Cervical spondylosis: the position of the pillow is too high when sleeping, the neck is pulled for a long time can cause cervical spondylosis attack, the patient will show numbness in the back of the head, neck pain, numbness of the limbs and other symptoms. (2) Occipital neuralgia: the cause of the disease is related to viral infection and demyelination of the occipital nerve, etc. At the onset of the disease, there will be pain in the back of the head, which may occur at night, and will affect the patient’s daily life in severe cases. When abnormal sensations occur in the back of the head during sleep, it is recommended to consult a doctor to clarify the cause of the disease and then target treatment.