Resting SpO2
% saturation
Blood oxygen saturation measured during sleep, representing baseline oxygenation in the absence of waking activity.
Typical optimal range 94% - 100%
Population median 96%
Key factors
- Sleep position
- Altitude of sleep environment
- Nasal congestion and airway patency
What affects this metric
- Sedatives and higher body weight both worsen overnight dips.
- Chronic lung conditions lower baseline saturation.
- Sleep apnea causes repeated dips through the night.
- Nasal congestion and back sleeping lower overnight saturation.
- Alcohol relaxes airway muscles and worsens dips.
- Altitude lowers it until adaptation.
References
Peer-reviewed sources supporting the key factors, contributing factors, and typical optimal range shown above.
- Rodríguez-Molinero A, Narvaiza L, Ruiz J, Gálvez-Barrón C. Normal respiratory rate and peripheral blood oxygen saturation in the elderly population. Journal of the American Geriatrics Society. 2013;61(12):2238–2240. doi.org/10.1111/jgs.12580
- Joosten SA, O'Driscoll DM, Berger PJ, Hamilton GS. Supine position related obstructive sleep apnea in adults: pathogenesis and treatment. Sleep Medicine Reviews. 2014;18(1):7–17. doi.org/10.1016/j.smrv.2013.01.005
- Kapur VK, Auckley DH, Chowdhuri S, et al.. Clinical practice guideline for diagnostic testing for adult obstructive sleep apnea: an American Academy of Sleep Medicine clinical practice guideline. Journal of Clinical Sleep Medicine. 2017;13(3):479–504. doi.org/10.5664/jcsm.6506
- Luks AM, Swenson ER. Pulse oximetry at high altitude. High Altitude Medicine & Biology. 2011;12(2):109–119. doi.org/10.1089/ham.2011.0013
- Ebrahim IO, Shapiro CM, Williams AJ, Fenwick PB. Alcohol and sleep I: effects on normal sleep. Alcoholism: Clinical and Experimental Research. 2013;37(4):539–549. doi.org/10.1111/acer.12006
This guide is general information, not medical advice. Talk to your clinician about your own results.