[Technique and interpretation of 24-hour blood pressure measurements]

Development of ambulatory repetitive recording of blood pressure during day and night under normal daily activity demonstrates a marked fall in blood pressure of normo- and hypertensive individuals during the night hours. Although no general consensus exists on normal values for such measurements, the upper normal limit appears to be 140/90 mmHg during the day and 120/80 mmHg during the night. This method also avoids the excessive rise in blood pressure induced by the physician (white-coat effect). Furthermore, it permits an exact assessment of efficacy of antihypertensive treatment. It may also provide means for better characterization of hypertension as risk factor in general, although there is still a lack of experience to estimate its cardio-vascular risk potency.