Delirium is an increasingly common multifactorial condition, especially in elderly and debilitated patients often undiagnosed and therefore untreated properly. It is a medical emergency with significant mortality rates.

Clarification about what delirium is and how to act upon suspicions of this clinical condition.

A non-systematic literature review was performed in PubMed (1990-2014), using the keyword “delirium” in combination with one other major search term to review areas including the Following: “epidemiology”, “clinical features”, “pathogenesis” and “evaluation”. Only original articles in english language were included.

The clinical presentation of delirium is variable but can be classified broadly into three subtypes—hypoactive, hyperactive and mixed. Risk factors for delirium are presented. The diagnosis of delirium is made on the basis of clinical history, behavioral observation and cognitive assessment. In view of the fact that cognitive impairment can be missed during routine examination, a brief cognitive assessment should be included in the physical examination of patients at risk of delirium. An algorithm of action in case of suspicions of delirium is proposed in this study.

Delirium is a serious cause and complication of hospitalization in elderly patients and should be considered to be a medical emergency until proven otherwise. Irrespective of the specific etiology, this condition has the potential to markedly affect the overall outcome and prognosis of severely ill patients, as well as substantially increasing health-care utilization and costs. For these reasons, prevention, early recognition and effective treatment of delirium are essential.