What Is the Difference Between Delirium and Dementia?

If mild forgetfulness is considered a normal part of getting older—misplacing keys, not remembering certain words, forgetting names—when is memory loss a concern?

Signs that point to more serious memory problems include difficulty performing everyday tasks such as driving or getting dressed, repeatedly asking the same questions, getting lost in familiar places, and confusion about people, places or time.

These symptoms are associated with dementia, a broad term given to the brain’s decline in memory and thinking skills. Dementia is a progressive condition, wherein symptoms worsen over a period of time. There are many types of dementia, but the most common is Alzheimer’s disease.

Delirium, on the other hand, comes on more suddenly (over a few hours or days) and is often related to an adverse reaction to medication(s), an infection or electrolyte imbalances. Examples of delirium symptoms include sudden confusion, difficulty speaking, personality changes and the inability to focus on one idea or task. 

A person experiencing memory-related problems, especially if symptoms are new or sudden, should be evaluated by a primary care provider. A thorough and careful medical history is the most important step to determine the cause.