Masked hypertension. A clinical state or measurement bias?

Abstract

Masked hypertension refers to a situation in which a patient has normal blood pressure in the office but elevated elsewhere, for instance in ambulatory blood pressure monitoring (ABPM) or when measured at home. The problem of masked arterial hypertension (the term proposed by Pickering et al. in 2002) has been known for several years. The occurrence of masked hypertension, its causes, criteria of diagnosis and management are not well understood. This paper reviews possible causes of this phenomenon, ranging from methodological issues to specific circumstances that may increase blood pressure outside the office (for instance smoking, high-level physical activity). Furthermore, we review the terminology and criteria of diagnosing masked hypertension, and views on its pathogenesis and clinical implications. New evidence shows that this phenomenon cannot be overlooked. Among patients with masked hypertension those with target organ damage such as left ventricular hypertrophy or carotid arterial lesions are frequently encountered. To define the significance of masked hypertension in everyday clinical practice prospective studies are required.