Masked hypertension: a common but insidious presentation of hypertension.

A patient has masked hypertension when his office blood pressure is less than 140/90 mmHg but his ambulatory or home blood pressure readings are in the hypertensive range. Several recent studies have demonstrated that cardiovascular risk is similar between those with masked hypertension and those with sustained hypertension. The prevalence of masked hypertension in Canada is not known, but data from other countries suggest rates greater than 8%. Physicians need to use careful clinical judgment to identify and treat subjects with masked hypertension. The present review discusses masked hypertension, its importance to clinical practice and some aspects of patient management.