Why You Wake Up at 3 AM – A Scientific Explanation
The article explains why people wake up at 3 AM, linking it to the evolutionary mechanism of 'segmented sleep.' Historical data show that sleep used to be biphasic, but with the Industrial Revolution, the phases merged. Modern science points to 90–110 minute sleep cycles, as well as hormonal fluctuations, blood sugar spikes, and external factors. Recommendations are given for sleep hygiene and cognitive-behavioral therapy.
The article explains why people often wake up around three in the morning, and argues that this is not always insomnia, but may be a manifestation of the evolutionary mechanism of 'segmented sleep.' Historians, citing archival evidence from Ancient Greece to the modern era, note that night rest used to consist of two phases: people went to bed after sunset, woke up for an hour or two to attend to matters, and then slept until dawn. With the Industrial Revolution and artificial lighting, these phases merged into a single block. Modern science shows that sleep is divided into cycles of 90–110 minutes, and closer to morning, waking becomes easier. Among the specific causes of nighttime awakenings are hormonal fluctuations (e.g., during menopause), blood sugar spikes, and consumption of caffeine and alcohol. A vicious cycle is also described: worries about insomnia cause stress, causing the brain to perceive night as a time of activity. To improve sleep, a regular schedule, limiting blue light, avoiding caffeine and alcohol, and, upon waking, engaging in a boring routine task are recommended. In severe cases, cognitive-behavioral therapy is advised.