Large observational research links several aspects of irregular sleep with higher risks across 172 diseases, including liver cirrhosis and gangrene, but the 172-disease figure covers six sleep traits collectively and does not prove that unstable sleep directly causes those conditions.
Mostly True
Irregular sleep isn’t just tiring—it’s dangerous. A massive study finds inconsistent bedtimes and unstable circadian rhythms linked to 172 diseases, including liver cirrhosis and gangrene.
FactVerify
Source: factverify.com
At a glance
Verified August 25, 2026Key Evidence
The strongest reported associations were specific rather than universal: routinely going to bed after 12:30 a.m. Was linked to a 2.57-fold higher risk of liver cirrhosis, while low day-to-day sleep-wake stability was associated with more than twice the risk of gangrene.
Coverage from ScienceAlert and ScienceDaily describes the 172 diseases as the combined result of analyzing six sleep traits, an important qualification to the original wording.
The evidence remains observational, so lifestyle, existing illness, and other factors could help explain the relationships.
The reporting
What the Evidence Shows
A large study followed participants for an average of 6. 8 years and examined six sleep characteristics, including bedtime, sleep regularity, circadian rhythm stability, duration, efficiency, and nighttime awakenings. Reports of the research say that associations involving these traits covered 172 diseases, with many conditions linked to only one sleep characteristic rather than to irregular sleep in general.
The findings were also reported as replicated in another large health database, which strengthens the consistency of the signal but does not turn the study into a causal experiment.
Primary trail
Verified Sources9
Open source
Major international sleep study links sleep patterns with 172 diseases
Massive Study Links 6 Sleep Traits to Risk of 172 Diseases : ScienceAlert
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Revision history
- Version 2August 25, 2026
The new reporting supports the existing Mostly True verdict but adds an important qualification: the study linked 172 diseases to six sleep characteristics considered together, not necessarily to inconsistent bedtimes or circadian instability alone. It also provides specific associations, including a 2.57-fold higher risk of liver cirrhosis among people who typically went to bed after 12:30 a.m. and more than twice the risk of gangrene among those with low day-to-day sleep-wake stability. These remain observational associations, not proof that irregular sleep directly causes each disease.
Mostly True - Version 1July 29, 2025
Initial published version
Mostly True