Our brain relies on cues to regulate our wake/sleep schedules. For example, when daylight hits our eyes, cells in the retinas signal our brain that it’s time to wake up. Temperature, night time, sleep, physical activity, etc. are all cues to keep our circadian rhythm in sync. However, as a natural part of aging we’ll experience changes in our sleep pattern such as earlier onset of sleepiness, early-morning awakenings, and an increased need for daytime napping.
When the circadian rhythm is altered or interrupted, it affects our physiology and behavior.
Several chronic sleep disorders can lead to circadian rhythm disruptions (CRD):
Ignored CRD-induced fatigue affects your health and safety-of-flight. For example, you may experience increased time to react, decreased attention to tasks, impaired memory and tendency to forget secondary tasks, increased distraction, and emotional irritability. To help minimize CRD after crossing time zones, try to reset your biological clock by getting out in the sun and daylight, staying active, and fitting in with the local eating and sleeping schedule. Consult a physician to diagnose and treat persisting sleep problems. Learn more in the FAA’s Medical Facts for Pilots: Circadian Rhythm Disruption and Flying publication (AM-400-09/3).
In this video from the Medical Self-Assessment: A Pilot’s Guide to Flying Healthy online course, discover how sleep environment, work shift, medical conditions, jet lag, and other factors can affect fatigue.