A clinical syndrome usually with acute onset, which involves abnormalities in thought and perception and fluctuating level of consciousness. It is caused by impaired brain function resulting from diffuse physiological change.


  • Infections e.g. malaria, trypanosomiasis, syphilis, meningitis, rabies, typhoid fever, HIV/AIDS
  • Pneumonia and urinary tract infections in elderly
  • Intoxication with or withdrawal from alcohol or other substances of dependence
  • Some medicines e.g. anticonvulsants and neuropsychiatric medications
  • Cerebral pathology e.g. head trauma, tumour
  • Severe anaemia, dehydration
  • Electrolyte imbalances, hyperglycemia

Clinical features

  • Acute onset of mental confusion with associated disorientation, developing within hours or a few days.
    Attention, concentration and memory for recent events is impaired
  • Reduced ability to think coherently: reasoning and problem solving are difficult or impossible
  • Illusions and hallucinations are common
  • Symptoms tend to fluctuate: patients feel better in the day and worse at night
  • Some patients may present with reduced activity and/or movement (hypoactive delirium)

Differential diagnosis

  • Acute psychosis


  • Guided by history and physical examination: aim at identifying the cause
    NB: drug history is very important!
  • CBC, blood glucose, RDT, renal function and electrolytes


Due to the complexity of underlying conditions, patients with acute confusional state should be referred to hospital
for appropriate management and investigation.

  • Identify and treat the cause such as substance and alcohol use disorders, diabetes, head injury or
    infections e.g. malaria, UTI, pneumonia in older people

Supportive treatment

  • Ensure hydration, control of fever, safe and quiet environment, constant monitoring
  • Withhold any unnecessary medicines, keep the use of sedatives and antipsychotics to the
    minimum necessary

If patient is agitated and acutely disturbed

  • Haloperidol 5 mg IM: repeat after 60 min if necessary
    • Continue with haloperidol 1.25-5 mg every 8 to 12 hours
  • Or chlorpromazine 25-50 mg every 8-12 hours
    (IM or oral)
  • Trifluoperazine 5-10 mg every 12 hours
  • If patient is extremely agitated
    • Diazepam 5-10 mg slow IV or rectal
      • repeat after 10-15 minutes if necessary
      • then oral diazepam 5-15 mg at night


    • Early diagnosis and treatment of underlying cause