Delirium or dementia: How to know the difference

More than 5 million people in the U.S. are living with dementia. It affects attention, memory, and judgment.

However, in the hospital, dementia is commonly misdiagnosed as delirium. A mistake that can delay treatment to slow the progression of the disease.

There are ways you can distinguish between dementia and delirium and get the help your loved one needs.

More than 7 million hospitalized patients in the U.S. will experience some form of delirium every year. Forty-five percent of those patients will have persistent delirium at discharge and 26% will experience delirium three months after being in the hospital. When delirium lasts that long, could it be something else?

“It is sometimes very difficult to differentiate between delirium and dementia because sometimes they are superimposed on each other,” said Dr. Barbar Kahn, a critical care physician at Regenstrief Institute at Indiana University.


Since cognition impairment is present in both conditions, how can you spot the difference?

“The main difference between delirium and dementia is delirium develops acutely and it tends to fluctuate. So the patient could be fine at one moment and very soon they can be fluctuating,” Kahn said.

Dementia is a chronic condition. Delirium is short-lived and mainly affects attention, while dementia mainly affects memory. And the most important distinction between the two conditions is that delirium is reversible, while dementia is not.

“If by a few months after discharge if they feel that the things are not getting better and those symptoms are persistent, then it might be time to go over to a specialized memory clinic,” Kahn explained.

To get a proper diagnosis and the help your loved one needs.

Kahn also reports that COVID-19 has sent delirium rates skyrocketing. Up to 75% of COVID-19 patients have been affected by delirium.