White coat hypertension: Physiological significance and prognostic value.

White coat hypertension and the white coat effect are common clinical probl ems. Although they have similar names, they do not correspond to strictly i dentical entities. The white coat effect is an increase in blood pressure induced by the physi cian. It may be observed for all degrees of mean blood pressure and it is u sually assessed by the difference between conventional and ambulatory blood pressure values. White coat hypertension is a qualitative status associati ng clinical hypertension and "normotension" outside the physician's office. In practice, the application of these definitions presents many difficulti es. The usual methods of evaluating the white coat effect are a poor marker of the true effect as measured by continuous blood pressure monitoring. White coat hypertension has many definitions, both with respect to the thre shold of clinical hypertension and to that of ambulatory normotension. Any attempt at evaluating the prognosis of these two conditions are faced with these considerations. However, the cardiovascular consequences which result appear to be mild and, usually, do not justify drug therapy. Their princip al implications are above all diagnostic as they may lead to the erroneous assumption of severe or drug-resistant hypertension.