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The Difference Between Delirium and Dementia

What Is Delirium?

Delirium is a sudden change in a person's mental state. It causes problems with attention, thinking, memory, and emotion. Delirium can change over the course of hours or days.

Delirium is a common condition that can be treated.  It is seen as a medical emergency. If delirium is not diagnosed and treated, it can lead to permanent problems. In some cases it can lead to death.

What Is Dementia?

Dementia is a range of signs that a person's brain is losing function. With dementia, a person's ability to think, remember, and communicate with others gets weaker over time. At first, a person may sometimes be forgetful or confused. Over time, he or she will have trouble following directions and doing daily tasks. The person will have trouble talking with and understanding others. Or forget who people are and not know where he or she is. The person may also be moody or restless.

How Are They Different?

Dementia and delirium are both health conditions that change a person's mental state. They do share some similar signs and symptoms. But they have different causes, treatment, and outcomes.

Dementia is a chronic condition that happens slowly over time. Delirium is a medical emergency that needs to be treated right away. Delirium can often be mistaken for dementia. In some cases, delirium and dementia can occur at the same time. Learn how the two are different, and what you can do to help a person who has signs of either or both.

Knowing the Difference




Common signs

Signs include forgetfulness and confusion. They will have trouble speaking with and understanding others.

Signs include seeming quiet, sleepy and confused, or restless and very distressed. Their sleep may be disturbed.

When signs appear

There is a slow change in mental state and behavior over months or years.

There is a sudden change in mental state and behavior over hours or days.

Thinking and attention

They may often seem confused. Over time, the person's thinking will not be sensible or logical. As the disease worsens, they will not be able to focus well. They will often not be able to talk with or understand others clearly. In some cases, they may see or hear things that others can't (hallucinations). They will not be able to remember events that just happened, and lose memory of events in the past. They may not remember who people are, or where they are. They may not recognize common objects.

They may be confused and disoriented. They may have trouble focusing and talking with others. It is likely that they will not be able to tell a health care provider about their symptoms. They may see or hear things that other can't (hallucinations). They may not be able to remember something that just happened.

Getting a Diagnosis

A person with signs of dementia or delirium needs to be diagnosed. In some cases, you can help. You can tell the health care provider how the person's mental state is different from his or her normal state. This can help the health care provider diagnose the problem.

Health care providers will look at different parts of a person's health. They will look at what medication a person is taking. They will find out if the person has an infection, or if he or she has an illness that has gotten worse. They may talk with the person to learn more about his or her mental state. And they may do tests to see if there may be a trigger for delirium.

When to Get Medical Help

Someone with dementia may also have signs of delirium. This can show that there is another problem.

If someone with dementia has sudden changes in mental state, call his or her health care provider right away. Or call 911 or your local emergency number. Tell the health care provider about the signs of delirium you have seen.

Author: StayWell Custom Communications
Last Annual Review Date: 6/30/2013
Copyright © The StayWell Company, LLC. except where otherwise noted.
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