Postpartum haemorrhage refers to bleeding after childbirth and can be primary (during or within 24 hours of delivery) or secondary (24 hours to 6 weeks after delivery). Primary causes include an atonic uterus, trauma, retained placenta, or coagulation disorders. Secondary causes include infection or retained membranes. Symptoms include heavy bleeding, dizziness, and low blood pressure. Treatment depends on cause but may include uterine massage, uterotonic drugs, surgery to repair lacerations, or hysterectomy in severe cases.