Light
The sleep cycle refers to the pattern of stages that our body goes through while we are asleep, including both rapid eye movement (REM) and non-rapid eye movement (NREM) sleep.
This refers to our internal biological clock that regulates our daily patterns of wakefulness and sleepiness.
Melatonin is a hormone produced by the pineal gland in response to darkness, helping regulate our sleep-wake cycle.
Insomnia is a sleep disorder characterized by difficulty falling asleep or staying asleep, leading to inadequate rest.