Hypertensive emergencies are serious cases of hypertension with very high disability and mortality rates. For this group of patients, to control the blood pressure to a safe range, the clinic will first use intravenous vasodilators, such as sodium nitroprusside or nitroglycerin, alpha-blockers, which act to dilate the blood vessels to bring down the blood pressure. Note that in the first hour the patient’s blood pressure decreases by about 25% and gradually decreases over the next 2-6 hours to a safe range, usually around 160/100 mmHg. If tolerated by the patient, gradually lowering the blood pressure to within the normal range over the next 24-48 hours can reduce the rate of disability and death of the patient.