The tooth pain is more severe at night, clinically it is the manifestation of endodontitis. For endodontic pain at night is a typical manifestation, but the cause is not particularly accurate, is currently believed to have two causes: 1, positional factors, people in the daytime in a sitting position or upright position, the head is in a high position, relatively speaking, the head of the blood supply is less, this time the swelling is not particularly obvious, the pain is naturally not particularly obvious, and the patient at night in a lying position, the head and the whole body is at a level, relatively speaking, the head and face will bear more blood, the swelling will be more serious, the pain will be more severe. 2, consider the psychological aspects of endodontic pain at night is more severe. In a horizontal line, relatively speaking, the head and face will bear more blood, the swelling will be more serious, the pain will be more powerful. 2, consider the psychological factors, people in the daytime work and study is relatively tense, the attention is all placed on the work and study, the pain is not very sensitive, and the people to the night, especially before going to bed, relatively speaking, in a more relaxed state, then you will feel the slight pain will become more painful. become more painful.