Читать книгу Sleep: The secret to sleeping well and waking refreshed - Prof. Idzikowski Chris - Страница 46

In normal usage ‘insomnia’ just means not being able to sleep. The inability to sleep can be caused by literally anything. Sometimes people talk about insomnia when they have not given themselves enough time to sleep, but when considered by a sleep disorder specialist, insomnia is often just regarded as a symptom and a cause is sought, e.g. depression (see page 156). Nowadays a sleep disorder specialist may regard insomnia as a disorder in its own right with very specific sleep-related causes (see pages 127-31). The changes in the usage of the word can cause confusion (particularly when surveys are conducted). An outdated classification simply described three types: