How sleep affects the development of dementia: lack of sleep and Alzheimer’s disease – December 2, 2023

Deep sleep does not occupy the predominant time in the structure of sleep, but it is this phase that charges us with energy and vigor.

“Deep sleep is the third phase of sleep and the most important,” says Nadezhda Podkorytova, chief physician of Invitro-Ural. — It’s happened to everyone that you seemed to sleep for a long time, but woke up broken – this means that your sleep moved into the third phase or too late, or got stuck in the second. The first stage is considered superficial sleep, and at the second stage the body gradually begins to relax, so some experience myoclonus – trembling of the arms and legs, often causing awakening, since the consciousness moves slower than the body into the third phase – deep sleep, when even external stimuli are unable to to wake. The fourth stage is called paradoxical sleep or the rapid eye movement phase: in this phase, the brain begins to work slowly, so a person often dreams at this stage. Somnologists have long been combining the third and fourth stages into one “delta sleep” or “deep sleep.”