Pillow too low may produce the following effects: 1, the pillow is mainly in the sleep to protect the cervical spine, too high or too low pillow is not suitable for the protection of the physiological curvature of the cervical spine. Pillow too low will cause cervical compression of blood vessels, nerves, resulting in ischemia of the posterior circulation, may cause dizziness, tinnitus, dizziness and other symptoms, but also the swelling of the nasal mucosa, congestion, or muscle pain, weakness of the symptoms. 2, sometimes sleep up will feel the shoulders have soreness, discomfort symptoms, with the pillow is too low, and the use of low pillow for a long time the blood circulation is not smooth, it will produce a numbness. Symptoms. So the pillow needs to choose the appropriate height in order to play the role of protecting the cervical spine, to avoid causing cervical spondylosis, to prevent the head, nose congestion.