A normal breathing rate for adults is 12 to 20 breaths per minute but you should expect your overnight breathing rate to be the low end of your normal.
In a healthy, relaxed adult, breathing should be calm and consistent throughout sleep. Breathing rate may increase during REM sleep when you're dreaming (especially if you're having an intense dream), but should revert to a slow pattern when you cycle into non-REM sleep.
However, over the course of the night - and over several nights - your breathing rate should remain relatively stable.
So what happens if it starts to change?
A change in overnight breathing rates could be as a result of:
- Hormones: Women have more variability in their respiratory rates, as respiratory rate trends correlate with menstrual cycles. Typically Respiration is slower at the beginning of the cycle and speeds up towards the end.
- Stress or Anxiety: Rapid and irregular breathing patterns are associated with increased anxiety.
- Intense exercise: Your respiratory rate may stay high for some hours after intense exercise.
Things to watch out for
While resting heart rate may meaninglessly change from day to day, respiratory rate generally does not, which makes it very easy to interpret and trust.
Overnight respiratory rate can be used to detect the early stages of an illness, as a person’s respiratory rate can indicate signs of an undetected medical problem.
In case of illness, your respiratory rates may be higher than normal. Moreover, they may stay relatively high for some time after symptoms have subsided, a sign that your body is still recovering.
A lower overnight breathing rate isn’t always ideal either. When combined with symptoms (like those above), it could indicate an issue with the electrical system of your heart. If you’re concerned, discuss these changes with your doctor.