This statistic is usually presented as a simple snapshot of how common “short sleep” is, using less than 7 hours per night as the threshold for adults.
A couple of important nuances:
- It’s self-reported in many surveys, so it’s an estimate rather than a precise measurement from wearables or sleep labs.
- “Less than 7 hours” isn’t automatically a diagnosis of sleep deprivation for every person, but it is widely used because many adults function best around 7–9 hours, and persistent short sleep is linked with higher health risk.
Sources
- https://www.nhlbi.nih.gov/health/sleep-deprivation
- https://my.clevelandclinic.org/health/diseases/23970-sleep-deprivation
- https://www.cedars-sinai.org/health-library/diseases-and-conditions/s/sleep-deprivation.html
- https://www.sleepfoundation.org/sleep-deprivation
- https://www.advocatehealth.com/health-services/sleep-medicine/sleep-deprivation
