Delirium (acute confusional state)

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Delirium (acute confusional state) is a sudden change in a person's mental status, leading to confusion and unusual behavior.

Symptoms of delirium usually develop over the course of several hours to a few days. Symptoms may fluctuate and often include:

  • Confusion and disorientation, including hallucinations, delusions, or illusions.
  • Disorganized thinking.
  • Short attention span.
  • Problems with the sleep-wake cycle.
  • Periods of hyperactivity alternating with extreme sleepiness.

Delirium may be caused by withdrawal from alcohol or drugs or medicines. The development or worsening of an infection or other health problem can also lead to delirium. People who have dementia are more prone to delirium.

The Health Encyclopedia contains general health information. Not all treatments or services described are covered benefits for Kaiser Permanente members or offered as services by Kaiser Permanente. For a list of covered benefits, please refer to your Evidence of Coverage or Summary Plan Description. For recommended treatments, please consult with your health care provider.