before nothing I am not a doctor, I am a simple programmer that likes to read about medicial sciencies. I've read in this book that the blood pressure it very important; is it really?

Then I have found by searching in Google:

Blood pressure has a daily pattern. Blood pressure is normally lower at night while you're sleeping. Your blood pressure starts to rise a few hours before you wake up.

If this is true, why does it happen?


Thanks for your time and advices.

  • Welcome to MedicalSciences.SE. The Mayo Clinic is a reputable site. What makes you question the information they provided? Jan 11, 2020 at 16:44
  • so sr. Chris I just want to know if this is true or no?
    – simon
    Jan 11, 2020 at 18:43
  • Welcome to Medical Sciences. In the future, you can consider mayoclinic.org an authoritative site. If they say it's true, you should assume it is until proven otherwise.
    – Carey Gregory
    Jan 12, 2020 at 5:44

1 Answer 1


"Daily patterns" in biology and medicine are referred to as "circadian" - circa means "around" or "approximately", and "dia" refers to "day" - "approximately daily".

Yes, as the Mayo Clinic site states, there is a circadian pattern to blood pressure. The primary pattern is that blood pressure (both systolic and diastolic) is higher during the day than at night. Like other aspects of cardiorespiratory function, blood pressure fluctuates according to metabolic needs.

Most of the circadian fluctuations for blood pressure specifically are due to external factors (unlike some other physiological parameters, which vary according to internal biological clocks): blood pressure is higher when you are doing activities that you tend to do in the day (like moving around), and lower when you do activities that you tend to do at night (like sleep).

Baumgart, P. (1991). Circadian rhythm of blood pressure: internal and external time triggers. Chronobiology international, 8(6), 444-450.

Floras, J. S., Jones, J. V., Johnston, J. A., Brooks, D. E., Hassan, M. O., & Sleight, P. (1978). Arousal and the circadian rhythm of blood pressure.

Mann, S., Craig, M. M., Melville, D. I., Balasubramanian, V., & Raftery, E. B. (1979). Physical activity and the circadian rhythm of blood pressure.

Smolensky, M. H., Hermida, R. C., Castriotta, R. J., & Portaluppi, F. (2007). Role of sleep-wake cycle on blood pressure circadian rhythms and hypertension. Sleep medicine, 8(6), 668-680.

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