[The significance of 24-hour blood pressure monitoring in the diagnosis and therapy of arterial hypertension].

The use of ABPM allows an improved assessment of blood pressure (BP) and therefore of the individual cardiovascular risk. It is able to identify patients who truly need therapy more exactly. Mostly patients with white coat hypertension who don't need therapy are identified. Furthermore, ABPM correlates more closely to target organ damage and to cardiovascular morbidity and mortality. This may be helpful to treat especially those patients who truly need therapy. BP exhibits a typical circadian rhythm with the highest values during the early morning hours and a decline during the night. A change of the day/night rhythm during shift work leads to an adaptation of BP rhythm. The early morning rise of BP and heart rate is accompanied by hemodynamic, rheological and biochemical alterations, which together may contribute to the increased frequency of vascular complications during the morning hours. The nightly decline of BP is often absent in patients with secondary hypertension and cardiac or renal organ damage. A lack of the nocturnal BP decline should therefore lead to further patients' evaluation. Elevated nocturnal BP seems to worsen the prognosis. ABPM offers better individual control of BP in patients on treatment and therefore is helpful to optimize the treatment. A more exact individual BP control during the awakening and sleeping period is possible as well as an avoidance of overtreatment. Patients could be protected both from prescription of too many drugs and from lowering BP too much. A further advantage lies in an improved control of patients with nocturnal hypertension.