There are many causes of perineal tear, mainly including labor, assisted delivery, long-term constipation, trauma, and excessive force during intercourse. 1. Childbirth: When the head of the fetus is delivered during labor, the vaginal opening and surrounding tissues are compressed and locally thinned, which may lead to perineal tearing, and in severe cases, anal damage. Therefore, during the observation of labor, it is necessary to correctly estimate the size of the fetus, understand the fetal position and the pre-disclosure site, and do a good job of protecting the perineum, and if necessary, make a lateral incision. 2. Assisted delivery: If it is difficult to assist delivery by head suction or forceps, it may cause perineal tear. 3. Prolonged constipation: If the patient has been squatting and sitting for a long time, or constipated for a long time, it will lead to dryness of the stool, and the lower part of the rectum will absorb the water of the stool, and then fecal stone will be formed, and if the patient exerts too much force to defecate, it may lead to perineal tear. 4. Trauma: when accidental injury occurs, external force on the perineum can lead to localized laceration. 5. Excessive force during coitus: this can lead to perineal tearing. If a woman suffers from vaginitis, this symptom is more likely to occur due to vaginal dryness and loss of elasticity. Care should be taken to avoid perineal tears caused by the above factors. Once a tear occurs, it is necessary to consult a doctor in time and give appropriate treatment according to the situation of the tear, and keep the local area clean in order to avoid infection.