Circadian rhythms
Circadian rhythms are 24-hour cycles that are part of the body’s internal clock, running in the background to carry out essential functions and processes. One of the most important and well-known circadian rhythms is the sleep-wake cycle.
Different systems of the body follow circadian rhythms that are synchronized with a master clock in the brain. This master clock is directly influenced by environmental cues, especially light, which is why circadian rhythms are tied to the cycle of day and night.
When properly aligned, a circadian rhythm can promote consistent and restorative sleep. But when this circadian rhythm is thrown off, it can create significant sleeping problems, including insomnia. Research is also revealing that circadian rhythms play an integral role in diverse aspects of physical and mental health.
How Does Circadian Rhythm Affect Sleep?
When people talk about circadian rhythm, it’s most often in the context of sleep. The sleep-wake cycle is one of the clearest and critical examples of the importance of circadian rhythms.
During the day, light exposure causes the master clock to send signals that generate alertness8 and help keep us awake and active. As night falls, the master clock initiates the production of melatonin, a hormone that promotes sleep, and then keeps transmitting signals that help us stay asleep through the night.
In this way, our circadian rhythm aligns our sleep and wakefulness with day and night to create a stable cycle of restorative rest that enables increased daytime activity.
