Teeth grinding during the day may be related to mental tension, teeth bite incongruity, intestinal parasites, gastrointestinal dysfunction and other diseases of the body. 1. Mental tension: if the mental stress is too great, it will keep the cortex of the brain in a state of excitement, which will make the masticatory muscles contract, and the phenomenon of teeth grinding will appear at night. 2. Uncoordinated bite: If there are problems with the development of the teeth, such as misaligned teeth, missing teeth, long teeth, etc., it is easy to make the patient’s occlusal relationship problematic, and the upper and lower teeth can’t match well, which can easily cause the patient to grind his/her teeth. 3. Other diseases of the body: when the body has intestinal parasitic infections, gastrointestinal dysfunction, vitamin D deficiency rickets, bladder stress and other diseases, may cause symptoms of teeth grinding. It is recommended that patients who always grind their teeth during the daytime should go to the hospital in time to check the cause and then carry out the corresponding treatment.