The complexity of masked hypertension: diagnostic and management challenges.

Masked hypertension, defined as discordant in-office normotension versus out-of-office hypertension, is present in approximately 10 % to 40 % of patients not receiving antihypertensive treatment. Not only are persons with prehypertension more likely to have masked hypertension, but they also frequently develop target organ damage before transitioning to established sustained hypertension. Moreover, the percentage of persons with masked hypertension increases in the presence of cardiovascular disease, diabetes, or chronic renal failure. The gold standard for diagnosing masked hypertension is the 24-hour ambulatory BP monitor (ABPM), but home BP monitoring (HBPM) has also been a useful alternative procedure. Importantly, initiating antihypertensive treatment exclusively with the use of in-office BP monitoring may result in almost one-third of patients remaining with high-risk masked uncontrolled hypertension, which underscores the importance of HBPM and ABPM as supplements to in-office BP monitoring for the effective treatment of hypertension.