What is Delirium?

If someone suddenly becomes confused, has trouble thinking, and starts behaving in unusual ways, that might be delirium. Medical experts call it a ‘neurocognitive decline’ that is temporary (“neuro” refers to the brain, and “cognitive” to thinking).

Delirium isn’t an illness. It’s a collection of symptoms caused by one or more health problems. It can be dangerous and needs to be treated.

Delirium can happen at any age but is most common in older adults.

Knowing how to recognize and deal with delirium helps prevent it. If delirium does happen to you or someone close to you, a quick response can prevent long-term complications. This can help an older adult stay independent longer, stay active, and continue to enjoy life.

What are the Signs of Delirium?

Delirium happens suddenly, over several hours. The symptoms come and go and are usually worse at night. A person experiencing delirium has a hard time making sense of what is happening around them. They might

  • Have trouble paying attention (or only pay attention to one thing)
  • Not be able to follow a conversation
  • Not make sense when they talk
  • See or hear things that other people do not see or hear
  • Seem nervous or scared or believe people are trying to hurt them
  • Be restless or angry
  • Be very quiet and withdrawn
  • Have trouble sleeping at night and staying awake during the day
  • Not know where they are

How is Delirium Different From Dementia?

Delirium is a set of symptoms. Dementia is a type of brain disease. Delirium symptoms can vary over a short period of time and then disappear, while dementia is a disease that progresses very gradually and does not improve.

A person with dementia can experience delirium too. Sometimes, delirium can look like dementia. The difference is that delirium comes on quickly. See or talk to a health care provider right away if any of the signs listed above suddenly appear, even if the signs come and go.


  • Comes on suddenly
  • Symptoms come and go, or change often
  • Continual trouble paying attention
  • Is different from the person’s regular behaviour
  • Often occurs in people with dementia


  • Symptoms begin very slowly and do not go away
  • Gradually gets worse
  • May have trouble paying attention, but this might go away
  • Sometimes gets worse in evenings (called sundowning)
  • A big risk factor for delirium

What Causes Delirium?

Delirium has many causes, and often, more than one cause. Specific events such as a fall, surgery, illness, or a trip to the hospital can bring on delirium. Also, some lifestyle habits, like not eating or drinking enough, can cause delirium. Chronic health conditions also play a role.

Events that can lead to delirum


Lifestyle habits that can lead to delirium


Other things that can make delirium more likely


How to Prevent Delirium

A healthy lifestyle is the best way to prevent delirium. This includes:

All these conditions can be a natural part of aging and are common. Talk to your primary care provider about finding support and check out the resources below!

Treatment Options

There is no single treatment for delirium.

Usually, the health care team will work with the patient and their family to learn about what caused the delirium. Then they will treat that cause. Usually, the delirium goes away. If not, the health care team will look for another cause.

Sometimes, noticing the delirium can save a person’s life, because it helps the health care team find and fix a serious illness.

Delirium in the Hospital

The hospital experience can cause delirium or make it worse. Untreated delirium can make recovery much harder. It might be the main reason someone needs to go into a care facility instead of going back home. It could be the reason someone ends up back in hospital soon after they leave.

If you are in hospital and think you are at risk for delirium, ask your hospital if they have a delirium prevention program. If so, ask to be part of it. Hospital staff play a big role in recognizing and treating delirium, but friends and family can help. Here’s what you can do:

  • Go to the hospital with older adults and stay with them as much as possible
  • If you are waiting with an older adult in an emergency room, make sure they eat, drink water, and stay as comfortable as possible
  • Bring them
    • things to remind them of home (for instance, photos, a blanket, food)
    • their glasses, hearing aids and extra batteries, medications, and dentures
  • Talk to the health care team about any symptoms that worry you. Because you know what the person is like most of the time, you can notice what’s different. You can help the health care team by telling them about the person’s usual behaviour, routine, and level of activity at home.

Five Ways Caregivers, Family Members, and Friends Can Help

When to go to the Hospital?

Often, home is the best place for someone experiencing delirium. It is a familiar place where they feel comfortable. But it’s important to know when to go to the hospital.

Go to the hospital when:

  • A person is physically ill in a way that required help right away, like a stroke or heart attack
  • A person is not safe—for instance, they are wandering out of the house or in danger of falling
  • A person is acting in an aggressive way that could be dangerous for themselves or others

Delirium Statistics…

In hospital

of older persons may develop delirium

In hospital

40% to 50% of older persons develop delirium after hip surgery

In hospital

of persons 65+ admitted to intensive care develop delirium

In residential care

Almost a million (about 979,000) Canadians aged 65 or older are at nutritional risk—a third of people in this age range


Confusion, Memory Loss, and Altered Consciousness

  • Advice on prevention and response from HealthLinkBC
  • Learn More

Delirium in the Older Person

  • This webpage from Island Health includes two award-winning videos about delirium
  • Learn More

Delirium Prevention and Care with Older Adults

  • A short and very helpful booklet from the Canadian Coalition for Seniors’ Mental Health
  • Learn More

Delirium in the Older Adult: A Family Guide—English version

  • A two-page fact sheet covering basic information in English
  • Learn More

Delirium in the Older Adult: A Family Guide—Punjabi version

  • A two-page fact sheet covering basic information in Punjabi
  • Learn More

Call 811 for 24/7 help

  • This will connect you to HealthLinkBC’s health service navigators. They can:
    • Answer basic health care questions and help you find your way around the health care system.
  • Call 8-1-1 (7-1-1 for the deaf and hard of hearing).
  • Available 24 hours a day, seven days a week.
  • Translation services are available in over 130 languages.
  • For non-emergency situations only.