Circadian disruption

Circadian disruption is a misalignment between the body's internal roughly 24-hour clock and the external schedule of light, activity, meals and sleep.

The master clock in the hypothalamus is set mainly by light reaching the eyes and coordinates rhythms in hormone release, body temperature, alertness and digestion. Shift work, jet lag, late-night screen exposure, irregular sleep times and some medical conditions can push these rhythms out of step. The result is difficulty falling asleep or waking at the desired time, daytime sleepiness, impaired concentration and, over the long term, associations with metabolic and cardiovascular problems.

Sleep specialists assess it with sleep diaries, wrist actigraphy and sometimes measurement of melatonin timing, and they classify formal circadian rhythm sleep-wake disorders by pattern. Standard approaches include timed light exposure, consistent schedules and, in some cases, melatonin under medical guidance. Circadian disruption is a recognized contributor to insomnia, and cannabidiol is not an established treatment for circadian rhythm problems.