The symptoms of clenching and grinding of teeth in sleep are the manifestation of diseases: 1, mental tension, excessive fatigue. 2, stomatological diseases, disorders of the occlusal relationship. 3, children’s micronutrient deficiencies, such as zinc deficiency. 4, digestive tract diseases. 5, nighttime sleep dreams, in the dream can appear clenching and grinding of teeth. 6, children’s parasitic diseases will also appear clenching and grinding of teeth. In short, there are many reasons, once the symptoms of clenching and grinding teeth should be timely consultation, detailed examination by the physician to find out the specific cause, the cause of treatment to achieve good results, involving pediatrics, dentistry, gastroenterology, psychiatry, etc., need to carry out a good diagnosis and differential diagnosis, to find the cause of the good treatment.