What is The Diurnal Rhythm of Blood Pressure?
A.One of the unique features of 24 hour monitoring is its ability to record blood pressure throughout the day and night, and to give a profile of the diurnal rhythm of blood pressure. Actually, most of our bodily functions show some sort of rhythmicity- this is true not only of blood pressure, but also the heart rate, and many of the hormones which regulate the circulation and other bodily functions. Blood pressure is typically highest in the morning hours, at the time when we get up, and then gradually decreases dauring the day. It is thus lower in the venings than in the mornings in most people. When we fall asleep there is a further fall of blood pressure, that is most pronounced during the first few hours of sleep. The average range of blood pressure over 24 hours is 10-20 mmgHg, although individual readingsw show a much wider range. This rhythm is largely determined by the cycle of rest and activity.
