søvnvåknesyklusen

The søvnvåknesyklus, or sleep-wake cycle, refers to the natural, recurring pattern of sleeping and waking that occurs over a 24-hour period. This cycle is primarily regulated by the body's internal biological clock, known as the circadian rhythm. External cues, most notably light, also play a significant role in synchronizing this rhythm with the environment.

During the day, exposure to light signals to the brain that it is time to be awake and alert. This suppresses the production of melatonin, a hormone associated with sleep. As daylight fades and darkness increases, melatonin production rises, promoting feelings of sleepiness and preparing the body for rest.

The sleep-wake cycle is not a simple on-off switch. It involves distinct stages of sleep, including non-rapid eye movement (NREM) sleep and rapid eye movement (REM) sleep, which cycle throughout the night. Disruptions to this cycle, such as those caused by shift work, jet lag, or certain medical conditions, can lead to sleep disorders, fatigue, and other health issues. Maintaining a consistent sleep-wake schedule is therefore crucial for overall health and well-being.