Delirium is a change in mental status. This a change in how the brain works which leads to extreme, shifting changes, including:

  • Changes in perception and sensation
  • Difficulties with ability to:
    • Focus
    • Sustain and shift attention
    • Think and reason rationally
    • Function normally
    • Communicate clearly


An injury or illness of the brain can cause delirium .Some of the most common causes include:

Brain Tumor
Brain Tumor

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Risk Factors

Factors that may increase your risk of developing delirium include:

  • Terminal illness, especially just before death
  • Serious illness, such as AIDS
  • Increased age
  • Severe sleep deprivation
  • Severe burn
  • Central nervous system problems such as stroke, seizures, tumors, and dementia
  • Surgery
  • Hospitalization
  • Visual or hearing impairment
  • Immobility
  • Dehydration
  • Severe constipation
  • Memory impairment
  • Lack of certain vitamins


Symptoms usually come on quickly. They can last for days, weeks, or longer. They also vary from mild to severe. Symptoms are often worse at night and may include:

  • Inability to pay attention
  • Confusion
  • Memory problems
  • Language disturbances
  • Disorientation, especially about:
    • Time of day
    • Where one is
    • Who one is

Severe symptoms include:

  • Misinterpretations—for example, thinking a doctor who is trying to help you is trying to hurt you
  • Illusions—for example, thinking someone is someone else
  • Hallucinations—seeing, hearing, or feeling things that are not there
  • Emotional disturbances—for example, suddenly becoming angry, fearful, or withdrawn for no apparent reason


You will be asked about your symptoms and past health. A physical exam will be done. The doctor will ask specific questions about:

  • Present injury or illness
  • Use of medicine or street drugs
  • Time when mental state changed
  • How and how fast the mental state changed

The doctor may suspect delirium after the exam. To determine a cause your doctor may need to run several tests such as:

  • Blood tests
  • Urine tests
  • Lumbar puncture —to test fluid around brain and spine
  • Kidney and liver function tests
  • Thyroid function tests


Treatment will focus on the cause. It may relieve the delirium. Symptoms may also need to be treated. Treatment plan may include combo of medicine, psychology, and support.

Treatments may include:


Options may include:

  • High-potency antipsychotic medications
  • Benzodiazepines—for delirium caused by alcohol withdrawal
  • Cholinergic medicine—for delirium caused by anticholinergic medicines
  • Vitamins—for delirium caused by low levels of vitamins

Some medicine may need to be stopped or changed.

Psychological Management

Psychological therapy may help you:

  • Feel safer and more comfortable
  • Improve the ability to function
  • Calm down and feel less anxious

Environmental and Supportive Interventions

Caretakers can take steps to help on a day to day basis. It may help to readjust to surroundings and lower anxiety. Examples of this intervention include:

  • Place a clock and calendar in the room.
  • Darken the room at night. Provide natural light during the day.
  • Keep the room quiet and noise-free.
  • Use of earplugs and/or eye shades during sleep.
  • Reminders of the day and time, where you are, and why you are there.
  • Place familiar objects around. Includes family photos or objects from home.


In general, delirium is difficult to prevent. There are many different causes. It can also come on suddenly.

The risk of delirium in hospitalized patients at risk for delirium may be decreased by:

  • Using memory aids
  • Listening to tools to help you relax
  • Doing light exercise
  • Using vision and hearing aids
  • Drinking plenty of fluids

American Psychiatric Association

National Institute of Mental Health


Canadian Psychiatric Association

Canadian Psychological Association


Delirium in hospitalized patients. EBSCO DynaMed Plus website. Available at: Updated July 26, 2018. Accessed October 1, 2018.

Inouye SK, Westendorp RG, Saczynski JS. Delirium in elderly people. Lancet. 2014 Mar 8;383(9920):911-22, commentary can be found in Lancet 2014 Jun 14;383(9934):2044.

Gleason O. Delirium. Am Fam Physician. 2003;67(5):1027-1034.

Mistraletti G, Pelosi P, Mantovani ES, Berardino M, Gregoretti C. Delirium: clinical approach and prevention. Best Pract Res Clin Anaesthesiol. 2012 Sep;26(3):311-26

4/29/2016 DynaMed Plus Systematic Literature Surveillance Litton E, Carnegie V, Elliott R, Webb SA. The efficacy of earplugs as a sleep hygiene strategy for reducing delirium in the ICU: a systematic review and meta-analysis. Crit Care Med. 2016;44(5):992-999.

Last reviewed September 2018 by EBSCO Medical Review Board Rimas Lukas, MD  Last Updated: 10/1/2018