Step 1: History

History and physical exam form the cornerstone of evaluation of a patient with delirium.

Begin by obtaining history from the patient if possible.

Precipitating factors

  • recent illness, new medication, substance use or withdrawal, environmental changes
  • post-fall, post-hospitalization, recent change of medication

Gather collateral history from caregivers, family, or facilities

Focus on:

  • Onset
  • Waxing/Waning characteristics
  • Baseline functioning
  • Associated symptoms
  • Falls
  • Recent medication changes or adherence
  • Recent changes of living environment
  • Loss of support system


Onset and course

  • acute, chronic or acute on chronic, waxing/waning, or constant
  • pattern: Same intensity through the day or waxing and waning through the day, variation from day-to-day

Duration of symptoms

Intensity, extent, or severity of symptoms

Associated signs and symptoms

  • nausea, vomiting, chest pain, dyspnea, headaches, weakness, numbness, abdominal pain
  • Associated symptoms: sob, rash, pain, increased somnolence, fever, delusions, hallucinations

Detailed medication review

  • Current medication list
  • Over-the-counter or herbal medications
  • Adherence to medication prescriptions
  • Any overdose or missed doses

Find out if symptoms started after initiation of a new medication.

NOTE: In the setting of dehydration or initiation of a new drug, a previously well-tolerated drug can have a deliriogenic effect as a result of reduced clearance or drug-drug interaction.

Substance abuse history

  • Alcohol
  • Illicit drug use
  • Opioid or benzodiazepine use
  • History of drug overdose or withdrawal