Delirium occurs when the normal sending and receiving of signals in the brain become impaired. This impairment is most likely caused by a combination of factors that make the brain vulnerable and trigger a malfunction in brain activity.

Delirium may have a single cause or more than one cause, such as a medical condition and medication toxicity. Sometimes no cause can be identified. Possible causes include:

  • Certain medications or drug toxicity
  • Alcohol or drug abuse or withdrawal
  • A medical condition
  • Metabolic imbalances, such as low sodium or low calcium
  • Severe, chronic or terminal illness
  • Fever and acute infection, particularly in children
  • Exposure to a toxin
  • Malnutrition or dehydration
  • Sleep deprivation or severe emotional distress
  • Pain
  • Surgery or other medical procedures that include anesthesia

Several medications or combinations of drugs can trigger delirium, including some types of:

  • Pain drugs
  • Sleep medications
  • Medications for mood disorders, such as anxiety and depression
  • Allergy medications (antihistamines)
  • Parkinson's disease drugs
  • Drugs for treating spasms or convulsions
  • Asthma medications
Sept. 05, 2015