Postpartum urinary retention is a condition in which urine is stored in the bladder after delivery and cannot be discharged smoothly. The causes of this condition are mainly related to the sudden decrease in pelvic pressure, excessive physical exertion during delivery, and anesthesia after caesarean section. The most common cause of postpartum urinary retention is the sudden decrease of pelvic pressure after delivery and the weakness of abdominal contraction due to the relaxation of abdominal wall muscles, which requires abdominal pressure and massage to promote urination. Secondly, normal delivery is too much energy and physical exertion for the patient, and the relaxation of abdominal muscles causes urinary retention. For patients who have a cesarean section, the effect of intraoperative anesthetic drugs is also a cause of urinary retention, which can gradually improve after the anesthesia subsides. In the case of acute urinary retention, catheterization is recommended first, and a catheter is left in place to drain the urine. In case of normal delivery, hot compresses and massage on the lower abdomen can be applied at the same time. As mentioned above, there are more reasons for postpartum urinary retention, and the common reasons are sudden reduction of pelvic pressure after delivery, relaxation of abdominal muscles, and anesthesia, which are more related.