Investigation of sleep and circadian rhythm disorders.

Diagnosis of a sleep disorders is multimodal. An overview is presented in this review. The medical history leads to a tentative diagnosis supported by questionnaires, sleep diary and objective methods. Examination may reveal upper airway problems in a patient suspected to have obstructive sleep apnoea or rigidity in an elderly patient with shouting during sleep, suggestive of rapid eye movement sleep behaviour disorder. The choice of diagnostic sleep test is based on the tentative diagnosis. Other tests (e.g., lumbar puncture, brain scan) may be indicated. Wearables pose the advantage of documenting the patients' habitual sleep and circadian rhythm.

The use of sleep questionnaires and sleep diary in the daily clinic.

Sleep quality is an important indicator for subjective well-being, for sleep disorders and for a long range of mental disorders and somatic illnesses. This review introduces the concept of sleep quality and describes how to assess sleep quality by use of a sleep interview, a sleep diary as well as generic and specific sleep questionnaires in the daily clinic. Examples of valid questionnaires are presented.