[Hypertensive emergencies. Clinical evaluation and therapeutic methods].

Hypertensive crisis may be defined as a condition characterized by a sudden rise in blood pressure, of varying length, that can damage arteries, arteriolas, and capillary vessels, producing impairment of end-organs. Hypertensive crises may occur under different clinical conditions, for this reason it is necessary to classify them according to their clinical context. Hypertensive crises are generally classified as hypertensive emergencies or urgencies on the basis of the clinical evaluation and according to the level of blood pressure and the presence of acute or ongoing end-organ damage. Hypertensive emergencies are conditions characterized by a great rise in blood pressure in the presence of acute or ongoing end-organ damages. A severe elevation of blood pressure is considered an emergency if there is an evidence of rapid or progressive damage to the central nervous system and myocardial, or renal deterioration. These are situations in which greatly elevated blood pressure must be lowered within one hour in order to reduce actual risk for the patient. Hypertensive urgencies are conditions in which severe elevations in blood pressure do not cause immediate end-organ damages but should be controlled within 24 hours in order to reduce potential risk for the patient. This group includes accelerated hypertension, severe elevation of blood pressure with minimal end-organ damages and no impending complications. In order to formulate a correct therapeutic plan and make the best use of the powerful antihypertensive drugs at our disposal, it is therefore necessary to distinguish hypertensive emergencies from hypertensive urgencies.