When measuring blood pressure, a distinction is made between the measurement in the doctor's office and the measurement outside the doctor's office, which is usually done as a long-term blood pressure measurement over 24 hours or as a home blood pressure measurement by the patient himself. The advantage of measuring blood pressure outside the doctor's office is the higher number of documented blood pressure values. The measurement of the blood pressure values in the familiar environment under everyday conditions also enables a more representative determination of the correct blood pressure. This fluctuates over the course of the day and depending on many influencing factors: for example, it is higher during excitement or physical exertion than during sleep.
During the measurement, the patient wears a portable measuring system consisting of a small recording device and an upper arm blood pressure cuff connected to it. Over a 24-hour period, the cuff inflates automatically at set intervals - every 15 minutes during the day and every 30 minutes at night. When the cuff inflates, the patient should hold one arm as still as possible at heart level. As the air is slowly released, the measuring device records pulse-synchronous amplitude fluctuations and thus determines the systolic and diastolic blood pressure. The small recording device stores the measured blood pressure values and the heart rate. A blood pressure profile is created from 40 to 60 measurements.
Long-term blood pressure measurement is a simple and risk-free method of obtaining important information about the cardiovascular system. During the examination, two values are measured several times: the upper (systolic) value and the lower (diastolic) value. In addition, the doctor receives information about the mean values during the day and night. The patient keeps a parallel log of his or her activities during a day with a normal daily routine. This makes it easier for the evaluating doctor to attribute changes in blood pressure to certain activities.
The recorded daily blood pressure profile serves on the one hand to diagnose arterial hypertension, on the other hand it is also important for monitoring the progress of a drug therapy. During sleep, blood pressure normally drops by 10 to 20 percent. If there is a suspicion of a disturbed day-night rhythm of the blood pressure, the long-term measurement can also provide important data here.