If the pillow is too high, dizziness, neck stiffness and pain, numbness of the limbs and other symptoms may occur. Pillow is too high when sleeping at night, the cervical spine will be in a state of straightening or even backward protrusion, ligaments, muscles, tendons, etc. will be in a state of tension, which will easily lead to cervical spondylosis in the long run, and then appear the above symptoms. Generally speaking, the suitable height of the pillow and the shoulder and arm muscle thickness, that is, when lying on the side of the pillow can make the neck straight, adults need about 6-9cm, children are a little lower.