Contractions after menstruation may be caused by sudden strenuous exercise, mental stress or prolonged maintenance of the same position. 1. Sudden and strenuous exercise: If the patient does sudden and strenuous exercise such as running or coitus after menstruation, it may stimulate the uterus, causing uterine contraction and even pain. Avoiding strenuous exercise before and after menstruation can prevent contractions. 2. Mental tension: if the patient does not pay attention to rest for a period of time, the mental tension may also lead to contractions, the patient can ensure adequate sleep, keep the mood relaxed to prevent contractions. 3. Keeping the same position for a long time: If the patient keeps the same position such as lying on the side or standing for too long, and does not pay attention to the appropriate change, it may lead to the uterus to be compressed for a long time and have contractions. There may be other reasons for contractions after menstruation, it is recommended to go to the hospital in time when the contractions are not relieved, under the guidance of the doctor to adjust the appropriate treatment.