Dismiss Modal

Causes

Who's at risk for delirium?

Choose a preferred language

Delirium is a sudden change in a person’s mental state and ability to think clearly. It happens most often in older people who have a serious illness. There's a greater risk if the person has dementia. But delirium can happen at any age. And it doesn't always happen in someone with a serious illness.

Delirium is seen as an emergency. It needs to be looked at by a healthcare provider right away.


What raises a person’s risk?

Delirium can happen while a person is being treated for an illness or other serious health condition. It can also happen after surgery. The person may be in a hospital or nursing home. Or they may be at home. Delirium often goes unrecognized in older adults.

A person is at risk for delirium if they have 1 or more of these:

  • Current dementia or cognitive impairment

  • A past episode of delirium

  • Depression

  • Are age 75 or older

  • Any serious illness, such as cancer, heart attack, or metabolism problem such as those linked to kidney or liver failure

  • Been admitted to intensive care in a hospital

  • Physical restraints

  • Been using or are withdrawing from drugs or alcohol

  • Past or current brain injury or disease

  • A bladder catheter

  • An infection

  • Broken bones, especially those that need surgery

  • Sleep problems because of light, noise, or other disruptions

  • Constant or severe pain that isn't well-managed

  • Fluid loss (dehydration)

  • Poor nutrition

  • Poor eyesight or hearing

  • Several tests or treatments in a short time

  • Not able to move or have pain with movement

  • Recent surgery with anesthesia


Medicines that raise the risk of delirium

Certain medicines can raise a person’s risk of having delirium. They include:

  • Prescription medicines. This includes sedatives, narcotics, antispasmodics, antibiotics, muscle relaxants, steroids, high blood pressure medicine, antacids, antidepressants, heart medicines, nonsteroidal anti-inflammatory drugs (NSAIDs) such as ibuprofen, and pain medicines, especially opiates.

  • Over-the-counter medicines. This includes allergy medicine, cough medicine, sleeping pills, and antinausea medicine. Diphenhydramine, found in many allergy and sleeping pills, is a very common cause.

  • Some herbal medicines

  • Psychoactive medicines


If you know someone at risk

Delirium is an emergency. If you think that your loved one has delirium, call 911 right away.

Author: Wheeler, Brooke

© 2000-2025 The StayWell Company, LLC. All rights reserved. This information is not intended as a substitute for professional medical care. Always follow your healthcare professional's instructions.

Find a doctor that's right for you.

From routine check-ups to groundbreaking treatments and beyond, Crestner Health is here to help you live your healthiest life.

Search our doctors
Related Articles
Read article
Brain Health
Understanding Reversible Dementias

Many factors can cause symptoms that mimic Alzheimer disease. These symptoms are known as reversible dementias. Unlike Alzheimer disease, they can be cured with proper treatment. Here are factors that may lead to reversible dementias.

Read article
Hospice Care
How Is Delirium Treated?

Delirium is treated by finding and treating the cause. It has many possible causes, such as reaction to medicines, changes in blood chemistry, infections, strokes, and acute heart diseases.

Read article
Urgent Care
Jaw Fracture

You have a broken jaw, or mandible bone. This is called a jaw fracture. It may be a minor break in the bone. Or you may have a major break, with the bone moving out of place. Learn how to care for the fracture as you heal.

Read article
Urgent Care
What is delirium?

Delirium is a sudden change in a person's mental state that fluctuates over short periods of time. Read on to learn more.