Hypertensive disorders are the second leading cause of maternal mortality in the United States. Hypertension in pregnancy is defined as blood pressure greater than or equal to 140 mm Hg systolic or greater than or equal to 90 mm Hg diastolic, measured on at least two separate occasions. Preeclampsia, as per the new guidelines, is characterized by the new onset of hypertension and either proteinuria or other end-organ dysfunction, more often after 20 weeks of gestation in a previously normotensive pregnant woman. New-onset proteinuria is not required for diagnosis of preeclampsia if there is evidence of other end-organ damage—a change from previous classifications. Although no screening test has yet proven accurate enough to predict preeclampsia, the use of a combination of the serologic factors seems promising. There are few data to support any specific blood pressure target in pregnancy. Although there is a general consensus on treating severe hypertension in pregnancy, there is a difference of opinion on treating mild to moderate hypertension in pregnancy. Avoiding uteroplacental ischemia and minimizing fetal exposure to adverse effects of medications are as important as avoiding maternal complications from high blood pressure during pregnancy. This review contains 2 figures, 4 tables, and 73 references.