What is delirium?

Delirium (new mental confusion) is a sudden change in mental status, or sudden confusion, that develops over hours to days. It is different from dementia, such as Alzheimer's disease, which is a chronic (long-term) state of confusion that develops and increases over time.

There are two types of delirium: hyperactive delirium and hypoactive delirium. Hyperactive means overactive (agitation, restlessness), while hypoactive means underactive (sleepy and hard to respond). Sometimes both types can occur together.

What are the symptoms of delirium?

The symptoms of hyperactive delirium include:

  • Anxiety
  • Restlessness
  • Rapid changes in emotion
  • Hallucinations

The symptoms of hypoactive delirium include:

  • Flat affect
  • Withdrawal
  • Apathy
  • Laziness
  • Decreased responsiveness

What causes delirium?

Some of the things that may cause delirium are:

  • Drugs
  • Changes in environment
  • Lack of sleep
  • Hormonal issues such as hyper-/hypo-thyroidism
  • Lack of oxygen to the tissues
  • Infections such as pneumonia or sepsis (an overwhelming reaction to infection)
  • Kidney or liver injury/failure
  • Alcohol or illegal drug toxicity/overdose
  • Pain
  • Dehydration

What is the risk of developing delirium?

Delirium shows up more often in patients who are in the hospital, and affects 10 to 30% of these patients. Also, more than 50% of people in high-risk populations are affected by delirium. These include people who have had surgery, as well as:

  • 25% of cancer patients
  • 30 to 40% of patients who have human immunodeficiency virus (HIV)
  • 60% of nursing home residents older than 75
  • 70% of intensive care patients
  • 80% of patients at the end of life (dying patients)

Patients are at a higher risk for developing delirium if they:

  • Have more than one illness
  • Take more than one type of medicine
  • Have had an illness for a long time
  • Have trouble hearing or seeing
  • Do not get enough sleep
  • Have had a stroke
  • Have Parkinson’s disease, dementia, or chronic liver disease
  • Abruptly stopped using alcohol or drugs (withdrawal)
  • Have burns
  • Are on dialysis
  • Are unable to move because of catheters or restraints
  • Are dehydrated

How is delirium diagnosed?

The doctor will test the patient for any problems in attention, memory, orientation, and visual ability. The doctor will diagnose a patient with delirium if he or she:

  • Is unable to focus or shift attention
  • Has changes in thinking from his/her usual self
  • Has rapid onset of problems in thinking (changes throughout the day)

What are the treatments for delirium?

Delirium is usually caused by other medical conditions, so it’s important to treat those conditions in order to treat delirium. The doctor will carefully review the patient’s:

  • Medical history
  • Physical exam results
  • Lab results
  • Drug use, including over-the-counter drugs, illicit drugs, and alcohol

Some ways to treat delirium include focusing on the patient’s environment. The person with delirium will do best in a quiet setting. The following are tips for caregivers/support people:

  • Help promote sleep and rest by reducing noise and distraction.
  • Reassure the patient and help him or her understand the environment.
  • Explain to the patient what is happening.
  • Bring familiar objects from home (for example, photos, a blanket, a bedside clock) to help make the patient more comfortable in an unfamiliar environment. Soothing music may be helpful, as well.
  • Feed the patient and give him or her drinks, if appropriate, throughout the day.
  • Encourage the patient to get out of bed, if it’s safe to do so.
  • Keep the patient oriented. Talk about current events and family news, as this provides mental stimulation. Reading out loud to the patient can be helpful.
  • Make sure the patient has nutritional food and stays hydrated.
  • Keep the patient awake during the day and exposed to sunlight. Avoid naps.
  • Try to ensure that the patient gets maximum uninterrupted sleep at night.

The patient should do as much as possible on his or her own. These actions (which may require assistance) include:

  • Using an interpreter to help understand care plans if there are language barriers.
  • Being involved in their treatment and asking the doctor any questions they may have.
  • Using eyeglasses and hearing aids to promote good vision and hearing.
  • Getting out of bed during the daytime. This includes sitting in a chair during mealtimes or walking when possible (with supervision, if necessary).

What medications are used to treat delirium?

Medicines for treating delirium symptoms include antipsychotic drugs (to treat agitation and hallucinations and to improve sensory problems). These include: Haloperidol (Haldol®), Risperidone (Risperdal®), Olanzapine (Zyprexa®), and Quetiapine (Seroquel®). Other medicines are also used, including benzodiazepines (these should be used only if the patient has alcohol or drug withdrawal).

Once symptoms improve, the patient should not stop taking medications suddenly. Instead, the dose should be gradually decreased. Consult with the doctor before the patient starts any medications.

What are the complications/side effects of the treatments for delirium?

Side effects related to antipsychotic drugs, especially for the elderly, include:

  • High illness and death rates
  • Stroke
  • Risk of developing higher-than-normal pulse rate with irregular heartbeats (this can occur when haloperidol is given through intravenously [into a vein])

Benzodiazepines may cause:

  • Drowsiness or increased agitation
  • Reduced control over behaviors
  • Uncoordinated muscle movements
  • Falls

What is the prognosis (outlook) for people with delirium?

The death rate among older patients in the hospital who have delirium is 22 to 76 percent. However, some patients recover completely with appropriate diagnosis and treatment. Lack of treatment can lead to stupor, coma, or death. Patients who are elderly and those who have HIV are less likely to fully recover.

People who have delirium may also have:

  • Longer hospital stays
  • Medical complications, such as pneumonia and pressure ulcers
  • Delirium that can last from several hours to several months

How can delirium be prevented?

The following suggestions might help prevent delirium:

  • Having a clock and calendar nearby
  • Having lots of lighting during the day
  • Limiting medicines that may cause delirium, or any extra medicines that are not needed
  • Drinking plenty of water and other fluids
  • Trying to walk or at least sit in a chair daily
  • Reporting to doctors and nurses any symptoms of an infection (cough, fever, pain, shortness of breath)
  • Family involvement in the patient’s treatment

What research is being done for delirium?

Research is being done on different medicines that can be used for treatment of delirium without negative side effects.


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This information is provided by the Cleveland Clinic and is not intended to replace the medical advice of your doctor or health care provider. Please consult your health care provider for advice about a specific medical condition. This document was last reviewed on: 1/20/2017…#15252