There are many reasons for teeth grinding in sleep, such as uncoordinated teeth and jaw clenching, intestinal parasitic infection, mental factors and so on. 1. Uncoordinated teeth and jaw biting: it may be due to heredity, which is manifested as misalignment of jaw biting and jaw biting, malformation of jaw biting and so on, and it may also be caused by usual bad habits, such as biting the pen, spitting out the tongue, biting fingers and so on, which leads to imbalance of upper and lower jaw biting and jaw biting and thus causes teeth grinding at night, and it is necessary to rectify the bad habits, which can relieve the symptoms. 2. Intestinal parasitic infection: due to the usual food do not pay attention to hygiene, coupled with their own resistance is relatively weak, resulting in roundworms in the stomach, roundworm output toxins will stimulate the nerves, so that the nerve excitation and lead to teeth grinding, usually wash your hands before meals, pay attention to personal hygiene, indoor ventilation, can alleviate the symptoms. 3. Mental factors: due to mental psychological overstress, fatigue, stress, etc. can cause the phenomenon of teeth grinding, it is recommended to maintain a relaxed mood, do not overstress, fatigue, pay attention to rest, can effectively relieve the symptoms. If the symptoms of teeth grinding can not be relieved, it is recommended to go to the hospital for examination and treatment.