[Insomnia: definitions, epidemiology and changes with age].

DEFINITIONS, EPIDEMIOLOGY AND CHANGES WITH AGE. Chronic insomnia is a disorder defined as a subjective complaint relating to the quality and/or quantity of sleep associated with daytime impact, and which must be present 3 nights per week for a period of at least 3 months. This is a common sleep problem in the general population and represents a significant proportion of reasons for consultation in the general practice. It requires early identification at all ages of life to allow the establishment of adequate care, which will have the benefit of both improving the quality of life of these patients in the short term and preventing the consequences of chronic insomnia.