If you require mental health crisis support, please contact your local mental health services, your GP, or telephone 111 or the emergency services.

Causes of delirium

Causes

The onset of delirium can be triggered by a person being physically unwell or when there has been a sudden change in medication. There are also some other factors that can increase the risk of experiencing delirium. 

Possible causes

  • Changes to prescribed drugs (and starting and stopping them).
  • A change to the person’s environment such as a house move, a move into a nursing home or a move between hospital wards.
  • Poor hearing or vision (including not having their glasses or hearing aid).
  • Lack of oxygen or low blood pressure.
  • Having an infection.
  • Pain and anxiety.
  • Constipation and, or problems passing urine.
  • Dehydration and a lack of important vitamins and calories.
  • Problems with the kidneys and liver.

Risk factors

  • People with dementia.
  • People who are dehydrated or have a poor appetite.
  • People with an infection (although low level infection may not show up on tests).
  • People who are constipated or have urine retention.
  • Older people.
  • People who have had surgery, particularly hip surgery.
  • Older people taking multiple medications.
  • People with sight and hearing difficulties.
  • People who are nearing the end of their life.
  • People who are in pain.
  • People in an unfamiliar or distressing environment.