A new study published in the Journal of Health Data Science shows that an irregular sleep schedule is far more dangerous than sleeping too little or too much. Researchers found that sleep timing has a stronger impact on health than sleep duration.
The research included about 90,000 adults. Participants wore fitness trackers that recorded their sleeping habits. Their health was tracked for over seven years to study the link between sleep patterns and disease risk. The findings were alarming: people with irregular sleep schedules faced a much higher chance of developing 172 different health conditions.
The study revealed that if a person sleeps at varying times on three or more nights per week, their risk of physical weakness triples. It also raises the chances of Parkinson’s disease by 37%, Type 2 diabetes by 36%, and kidney failure by 22%. These results prove that sleep timing is crucial for long-term physical health.
The researchers also found that going to bed and waking up at fixed times each night reduces the risk of 192 diseases by up to 20%. A regular bedtime helps balance hormones, boosts the immune system, and reduces inflammation. In contrast, irregular sleep causes an increase in white blood cells and certain proteins. This leads to chronic inflammation — a condition linked to heart disease, metabolic problems, and other serious illnesses.
Sleep experts stress that sleep consistency is vital in today’s busy world, where late-night screen use and irregular routines disturb natural body rhythms. While sleep duration matters, irregular timing can cause both mental and physical harm. Consistency is the foundation of restorative, health-protective sleep.
The researchers admitted the study had some limits since it only used one week of sleep data. They suggested more long-term studies to confirm the results. Still, the evidence strongly supports the idea that a steady sleep routine greatly improves long-term health.
In a fast-paced world filled with digital distractions and stress, maintaining a regular sleep schedule is becoming harder but more important. Health professionals urge people to follow consistent sleep and wake times to improve mental health and prevent chronic diseases.
