Postpartum hemorrhage is excessive bleeding from the genital tract after childbirth, defined as blood loss over 500ml. It can be immediate or occur more than 24 hours later. The main causes are problems with uterine contraction leading to bleeding from the placental site, or lacerations during childbirth. Prevention focuses on correcting anemia during pregnancy and using oxytocin or ergometrine to aid uterine contraction after birth. Treatment seeks to stop the bleeding through massaging the uterus or medications, and replace lost blood volume through transfusions or fluids while the cause is addressed.