What is the primary difference between delirium and dementia?

• A. Delirium is acute and fluctuating; dementia is chronic and progressive
• B. Delirium is chronic and progressive; dementia is acute
• C. Both are acute
• D. Delirium is acute and fluctuating; dementia is chronic and progressive

Answer: (D)

The essential idea is how quickly the condition appears and how its symptoms change over time. Delirium is an acute disturbance in attention and cognition that comes on over hours to days and tends to fluctuate in intensity throughout the day. It often signals an underlying medical issue, such as infection, medication effect, dehydration, or metabolic disturbance, and addressing the root cause can reverse or lessen the symptoms.

Dementia, in contrast, is a long-standing, progressive decline in cognitive function that develops slowly over months to years. It involves steady, chronic problems with memory, language, and daily functioning, and it generally worsens over time rather than fluctuating in a single day. Many forms of dementia are not reversible, though some interventions can help manage symptoms and slow progression.

So, the correct description matches delirium as acute and fluctuating and dementia as chronic and progressive, highlighting the key difference in onset and course.