Delirium Differential Diagnoses

Updated: Apr 25, 2019
  • Author: Kannayiram Alagiakrishnan, MD, MBBS, MPH, MHA; Chief Editor: Glen L Xiong, MD  more...
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Diagnostic Considerations


AIDS-related complex


Dementia is one of the most important risk factors for delirium. It often coexists in patients who are hospitalized. Delirium may be a risk factor or marker for the development of dementia. The safest rule is to consider delirium when recent changes in an elderly patient's level of consciousness and cognition have occurred in an acute care setting.

Patients with hypoactive withdrawn delirium may be misdiagnosed as depressed. Depressed patients also may have cognitive symptoms, but the patient's level of consciousness is normal.

Delirium may have to be differentiated from psychotic illnesses such as schizophrenia because both have psychotic features. In delirium, the patient often does not have a previous history of serious psychiatric illness. The onset of symptoms of delirium is acute or subacute, the hallucinations predominantly are visual and fluctuate, and the patient has impaired memory and orientation and clouding of consciousness.

Differential Diagnoses