Hypertensive emergencies require prompt and aggressive treatment to prevent target organ damage and death. A variety of neurologic, cardiac, renal and other conditions may underlie a hypertensive crisis. A number of highly effective drugs are now available to treat hypertensive crises, including well-known agents like sodium nitroprusside and diazoxide, as well as newer drugs such as nifedipine and captopril. Some older medications have been superseded by newer agents.