To establish diagnosis, patient must have both 1 and 2 and either 3 or 4.

Recognition of a patient's state of confusion is only the beginning of a clinical odyssey that can implicate a huge spectrum of diagnostic possibilities. Among these are delirium, depression, dementia, and sensory deprivation. However, with appropriate physical examination and laboratory studies, collateral history, and clarification of time course for the symptom complex, the cause of confusion need not remain confusing.