Photo Credit: Master1305

Winter affects sleep schedules through daylight shifts, reduced sunlight, and seasonal illness, potentially negatively impacting sleep quality and overall health.

“The winter months can bring challenges to (patient) sleep schedules,” according to Rosie Osmun, certified sleep science coach at Amerisleep. 

These disruptions often stem from the transition to daylight saving time (DST), reduced daylight exposure, and seasonal illnesses, all of which can negatively affect patients’ sleep and overall health in various ways. 

Daylight Saving Time Shift

DST ended for most of the U.S. on Sunday, November 3, 2024, leading to circadian misalignment. 

In a position statement for the Journal of Clinical Sleep Medicine, Dr. Muhammad Adeel Rishi and colleagues noted, “The light/dark cycle is key in circadian entrainment. The acute alterations in timing due to transitions to and from DST contribute to misalignment between the circadian biological clock and the light/dark cycle (or photoperiod), resulting in not only acute personal disruptions but significant public health and safety risks.” 

Dr. Rishi wrote that transitions both into and out of DST have been associated with mood disturbances and suicide. 

Reduced Daylight Exposure  

Limited daylight in winter lowers vitamin D levels essential for serotonin production.

In a literature review published in Sleep Medicine Reviews, Laura Huiberts, MSc, and colleagues reported that “having sufficient vitamin D levels in the brain increased the expression of the enzyme tryptophan hydroxylase 2, which is necessary for sufficient serotonin production.” 

Huiberts reported that a lack of sufficient serotonin in the brain could negatively affect mood, cognition, impulse control, and social behavior. 

Colds & Flu 

Seasonal illnesses like colds and flu disrupt sleep through symptoms such as snoring, coughing, and fever. While over-the-counter medications alleviate symptoms, ingredients like alcohol, pseudoephedrine, and diphenhydramine can interfere with deep sleep cycles, leading to sleep deficiency. 

The National Heart, Lung, and Blood Institute reported that sleep deficiency is linked to many chronic health problems, including heart disease, kidney disease, high blood pressure, diabetes, stroke, obesity, and depression. Sleep deficiency is also linked to a higher chance of injury in adults, teens, and children. 

Strategies for Improving Sleep 

To mitigate patients’ winter sleep challenges, Osmun recommends clinicians suggest: 

• Using a sunrise alarm clock to support natural sleep-wake cycles. 
• Maintaining a consistent sleep schedule to stabilize natural circadian rhythms. 
• Enhancing sleep environment with optimal bedding and room temperatures consistently set to between 60–70°F. 

These measures can help patients maintain healthier sleep patterns during winter’s disruptions.