Sleep is a complex neurobiological process that takes up approximately one third of our lives. Although it resembles an interval of "relaxation" at a superficial level, the brain is quite active during this period. Sleep consists of discrete, structured phases, during which various parts of the nervous system are activated and deactivated. It is necessary, not only for the rejuvenation of the body, but also for the processing of information that the brain acquired during wakefulness. Sleep disorders are very common. Most of them are part of the nosological spectrum of Neurology. However, the architecture, quantity and quality of sleep can be disturbed by numerous non-neurological conditions: obesity, stress, mental illness, pregnancy, shift work, cardio-respiratory diseases, pain, etc. The most prevalent sleep disorder is insomnia. Although it is usually transient, it can become chronic, impairing quality of life to a significant degree. The rest of the sleep disorders can be categorized as follows: