[Insomnia]

Insomnia is frequently met in everyday medical practice. Half of the population can present this symptom during their life-time. Objective impairment of sleep, as well as complaints of patients, are various and require investigations. Two forms of insomnias, transient and chronic, can be identified. The former is mainly factual and the latter is consecutive to a longstanding organic or psychiatric condition or constitute what is generally referred to primary chronic insomnia. The form, the duration, the severity and the etiology are important clues for the choice of treatment, notably the prescription of hypnotics.