Pre-eclampsia (PE) and eclampsia is the leading cause of maternal death in the UK and a major cause of perinatal morbidity and mortality. PE is predominantly a disorder of first pregnancy. There is a genetic component. PE is a syndrome without a defined cause. The variability with which it presents, and the speed with which it progresses, make it hard to diagnose. High blood pressure and proteinuria, with or without oedema, are classic symptoms but it may also present in an unusual way, eg as jaundice; as proteinuria with normal blood pressure; as intra-uterine growth retardation; as abdominal pain. The placenta becomes "sick" because of restricted blood flow from the mother; an unknown factor causes disturbances to spread throughout the mother's circulation which may lead to blindness, strokes, liver rupture and death. Delivery of the placenta is the only effective treatment, but preventive options being explored include aspirin and calcium supplements.