Hypertensive states during pregnancy include preeclampsia/eclampsia, gestational hypertension, chronic hypertension, and preeclampsia superimposed on chronic hypertension. Preeclampsia is a medical condition where hypertension appears in pregnancy, usually in the second or third trimester, in association with significant proteinuria. Eclampsia is a new onset of seizures in a woman with preeclampsia. Accurate preeclampsia statistics are difficult. The single most significant risk factor is having had preeclampsia in a previous pregnancy. There are many different mechanisms for preeclampsia that may cause endothelial dysfunction; with subsequent damage to the maternal endothelium, kidneys and liver. Preeclampsia is a major cause of maternal and perinatal mortality and morbidity worldwide. Intensive monitoring in women who are at increased risk may lower the incidence of adverse outcome. A pregnancy complicated by severe preeclampsia, especially at term, should be terminated; otherwise, expectant management may be indicated.