Definition – What are blood pressure fluctuations?
The term blood pressure fluctuations means that blood pressure takes on different values at different times. These can occur physiologically, i.e. naturally, as well as due to illness. Physiological blood pressure fluctuations include first- and second-order fluctuations.
The former are the different blood pressure values during systole and diastole. Second order blood pressure fluctuations describe the variability of blood pressure during inhalation and exhalation. Even at night or in stressful situations, the human circulation reacts with blood pressure changes. However, it is also possible that disease-related processes lead to blood pressure fluctuations. These can lead to dizziness or even loss of consciousness.
Causes
Among the naturally occurring blood pressure fluctuations are the first and second order blood pressure fluctuations. The heartbeat is divided into systole and diastole. The systole describes the phase of tension of the heart and the phase in which the blood is ejected into the circulation.
Diastole is the relaxation phase of the heart. If the blood pressure is measured, two values are given, for example someone has a blood pressure of 120/80 (spoken 120 to 80). These two values are systolic and diastolic blood pressure.
The first value, the higher, is the systolic and the second, the lower, is the diastolic. This physiological fluctuation between systolic and diastolic blood pressure is called first order blood pressure fluctuation. Second order blood pressure fluctuations are a decrease in blood pressure during inhalation and a renewed increase during exhalation.
The duration of these fluctuations per cardiac cycle depends on the breathing rate. A further fluctuation of blood pressure during the day is the drop in blood pressure during the night. Compared to the daily average, blood pressure falls between 10-20% at night. If high blood pressure is present, this drop can be pathologically absent. Affected persons whose blood pressure does not drop by at least 10% at night are called “non-dippers” and should be subjected to high blood pressure therapy.
Diagnosis
The diagnosis can be made in different ways. In the foreground is the measurement of the blood pressure. However, since a single measurement cannot provide information about fluctuations in blood pressure, a blood pressure measurement should be carried out over 24 hours.
For this purpose, a blood pressure monitor is attached, which measures the blood pressure at regular intervals during the day and night. With the help of these so-called long-term blood pressure measurements, fluctuations can be recorded and it can be observed whether the blood pressure drops sufficiently during the night’s rest. It is useful for the patient to write down what he or she has done at different times of the day to be able to understand why the blood pressure has behaved in this way.
If, for example, there was an argument or other excitement, the evaluator should know this, as this may result in an increase in blood pressure. Here it goes: Blood pressure – How do I measure it correctly? In order to be able to determine a disturbance in orthostasis, i.e. a drop in blood pressure after getting up, a so-called Schellong test can be carried out. In this test the patient’s blood pressure is measured alternately in a lying and standing position.
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