According to somnologists, proper sleep is even more critical for survival than food. We collected expert materials on why we sleep, what techniques will help you fall asleep quickly and what to do if you have insomnia. Researchers are actively studying the functions and role of sleep in human life, and despite different scientific approaches and points of view, they agree that healthy sleep helps to cope with stress, stimulates the immune system and improves heart function. At the same time, a third of the world’s population does not get enough sleep regularly.