[Medical stress and blood pressure]

BP measurement by a physician may trigger a blood pressure and heart rate increase often referred to as the white coat effect. This pressure response may occur both in normotensive and hypertensive subjects. The identification of such individuals is usually not possible on a clinical basis. This identification is however important because white coat effect and permanent hypertension do not share the same prognosis, the white coat effect being associated with a low rate of cardiovascular complications. To avoid an important overestimation of the real blood pressure level due to this white coat effect, it is possible to increase the delay before blood pressure measurements (beyond 15 minutes) or to take into account measurements made by nurses. Reading may also have a favorable consequence. However, a blood pressure recording outside the office, that is an ambulatory or a home blood pressure measurement, is the only way to confirm the presence of a white coat effect. The decision to treat is based on this measurement.