[Are mercury sphygmomanometers obsolete?].

The measurement of blood pressure during medical visits is limited in its diagnostic, prognostic and therapeutic value by physiologic variability of hypertension and measurement errors. Repeated measurements reduce the effect of spontaneous variations of blood pressure. They allow a more secure assessment of real tension. Regular training for proper technique and elimination of arbitrary preference for rounded last digits or automated recording minimize erroneous measurements. By the multitude of recorded parameters the ambulatory measurement over 24 hours and the self-assessment of blood pressure provide a representative diurnal profile superior to individual measurements at the doctors office. Each of the two methods has its own field of application, although prognostic and therapeutic aims seem similar. The continuous recording over 24 hours is suited for initial assessment and identification of hypertensive patients. Self-assessment of blood pressure has its use for long-term follow up and optimization of therapy. Both methods are complementary and only limited from wider use by lacking internationally accepted normal values and standardization of available devices.