Sleep and hypnotics.

Sleep is an enigma and the clinical importance of disturbed sleep is not clear. Much has been learnt in the past 25 years of the physiology of normal and abnormal sleep. Complaints of insomnia can be related to several causes--normal extreme patterns, psychiatric, physical, specific and drug-related. The treatment of insomnia is essentially that of the primary condition. Hypnotics have a limited role and their use should always be carefully considered.