A circadian rhythm (/sərˈkeɪdiən/), or circadian cycle, is a natural oscillation that repeats roughly every 24 hours. Circadian rhythms can refer to any...

Circadian rhythm sleep disorders (CRSD), also known as circadian rhythm sleep-wake disorders (CRSWD), are a family of sleep disorders which affect the...

Light effects on circadian rhythm are the response of circadian rhythms to light. Most animals and other organisms have a biological clock that synchronizes...

environment, primarily daylight and darkness. Circadian clocks are the central mechanisms that drive circadian rhythms. They consist of three major components:...

a person's circadian rhythm (biological clock) compared to those of societal norms. The disorder affects the timing of biological rhythms including sleep...

blue-green algae, see bacterial circadian rhythms). The best studied rhythm in chronobiology is the circadian rhythm, a roughly 24-hour cycle shown by...

Non-24-hour sleep–wake disorder (non-24 or N24SWD) is one of several chronic circadian rhythm sleep disorders (CRSDs). It is defined as a "chronic steady pattern...

Bacterial circadian rhythms, like other circadian rhythms, are endogenous "biological clocks" that have the following three characteristics: (a) in constant...

is a temporary physiological condition that occurs when a person's circadian rhythm is out of sync with the time zone they are in, and is a typical result...

Irregular sleep–wake rhythm disorder (ISWRD) is a rare form of circadian rhythm sleep disorder. It is characterized by numerous naps throughout the 24-hour...