Hypertension is a common clinical problem in the Emergency Department. Beside homologated therapeutical approaches it is necessary in primis to consider the problem in a clinical context and in an appropriate nosographic scheme in order to provide a rational approach to the treatment. In this paper the authors review the nosographic and therapeutical approaches previously reported in literature and then state their proposals derived by their daily experience at the Emergency Department. In authors' opinion it is of primary importance to distinguish between hypertensive crises and simple blood pressure rise. For this end it seems useful to define four syndromic classes: A. Real Hypertensive Crises: 1-Hypertensive Emergencies, 2-Hypertensive Urgencies. B. Simple Blood Pressure Rise: 1-Stable Uncomplicated Hypertension, 2-Transient Hypertension. According to this classification the majority of patients referring to Emergencies Departments for elevated blood pressure can be included in the last two classes. The authors suggest a step-by-step approach to the treatment beginning with benzodiazepines, loop diuretics, beta-blockers or clonidine or ACE inhibitors or calcium channel blockers; In an elevated percentage of cases benzodiazepines alone are effective in appropriately lowering blood pressure.