and sleep-related circadian rhythm clearly:
“During the day, light exposure causes the master clock to send signals that generate alertness, 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.”
Messing up the rhythm
There are myriad ways to disturb the circadian rhythm sleep-wake cycle:
- Shift work (such as overnights) that run counter to naturally dark and light times of day
- Erratic work hours (some nights, some days)
- Travel across multiple time zones (especially international)
- Poor sleep habits, irregular bedtime and waking time
- Staying up late or waking up too early on a regular basis
- Some medications
- Stress, anxiety, depression and other mental health issues
- Brain injury
- Blindness (the lack of the brain’s ability to perceive daylight and darkness)
The consequences of disturbed circadian sleep rhythms may sound familiar:
- Insomnia
- Sleep loss
- Problems waking up in the morning
- Daytime fatigue
- Depression, anxiety and stress
- Jet lag
- Shift work sleep disorder (SWSD)
- Irregular sleep-wake disorder
The NIH warns consumers about the potential dire…