Delirium: Risk, Presence, & Caring

Delirium is a clinical syndrome involving an acute change in mental state typically involving variable attention, memory, and thinking. Delirium is a common and serious syndrome. It is a risk factor for increased hospitalization days, care cost, dementia, and mortality. Delirium can occur at any age, but is mostly identified among older individuals. 

Up to 60% of hospitalized seniors experience delirium at some point during hospitalization. However, delirium is preventable in 30-50% of cases. For these reasons, identifying delirium risk and presence as well as caring for delirium is vitally important.  

Delirium Versus Dementia

Delirium is different from dementia.


  •  Delirium comes on quickly, in hours or days.
  • Signs of delirium can change from one day to the next.
  • Delirium can make memory and thinking problems worse.
  • Delirium is usually reversible, often lasts days to weeks, but may last longer.


  •  Dementia is usually a non-reversible condition.
  • Dementia is the loss of cognitive functioning — thinking, remembering and reasoning — and behavioral abilities to such an extent that it interferes with a person’s daily life and activities.
  • Dementia is a disturbance of thinking. It develops slowly over months or even years.
  • Patients with dementia are more likely to develop delirium.

Risk Factors for Delirium

Experts think delirium is caused by a change in the way the brain is working.

Senior woman in hospital gown looking out the window

This can be caused by:

  • Low oxygen levels
  • Chemical changes in the brain
  • Infections
  • Severe pain
  • Sleep disturbances
  • Anemia
  • Dehydration causing electrolyte abnormalities
  • Prolonged immobility
  • Constipation
  • Urinary retention
  • High-risk medications, including sedatives and pain medications
  • Withdrawal from medications and substances (i.e. alcohol, cocaine)

Signs of Delirium

  • Appearing agitated or aggressive
  • Increased fatigue
  • Increased time sleeping
  • Using inappropriate words
  • Not following directions
  • Limited attention span
  • Emotional changes

How to Help a Patient with Delirium

Man in hospital holding hands with his family member
  • Avoid confrontation
  • Gentle reorientation if needed
  • Maintain day/night orientation — lights on during the day, limit daytime naps
  • Keep daily board information updated/visible
  • Offer a snack
  • Mobilize
  • Speak softly and use simple words or phrases
  • Talk about family and friends
  • Bring glasses, hearing aids, dentures 
  • Decorate the room with calendars, posters or family pictures. These familiar items might be reminders of home
  • Provide the patient with favorite music or TV shows. If your loved one has delirium, we might ask you to sit and help calm them


  • American Psychiatric Association. Diagnostic and statistical manual of mental disorders, (DSM-5): American Psychiatric Publishers; 2013. Oh ES, Fong TG, Hshieh TT, Inouye SK.
  • Delirium in Older Persons: Advances in Diagnosis and Treatment. Jama. 2017;318(12):1161-74. Inouye SK, Bogardus ST, Jr., Charpentier PA, Leo-Summers L, Acampora D, Holford TR, et al.
  • A multicomponent intervention to prevent delirium in hospitalized older patients. The New England journal of medicine. 1999;340(9):669-76. Marcantonio ER, Flacker JM, Wright RJ, Resnick NM. Reducing delirium after hip fracture: a randomized trial. J Am Geriatr Soc. 2001;49(5):516-22. 

View and download UF Health’s Patient/Family Guide to Delirium