Delirium is typically characterized by which features?

• A. Rapid Onset, Brief Duration, Fluctuating Course
• B. Gradual Onset and Steady Progression
• C. Permanent Impairment With Fixed Course
• D. No Change in Consciousness

Answer: (A)

Delirium is an acute confusional state marked by a sudden change in mental status with impaired attention and awareness, developing over hours to days and often fluctuating in severity. The pattern that fits best is rapid onset, brief duration, and a fluctuating course, reflecting how the symptoms wax and wane throughout the day as the underlying cause is addressed or evolves. This contrasts with dementia, which typically has a gradual onset and steady progression, and with conditions that imply permanent impairment with a fixed course. Delirium also involves altered consciousness, unlike situations where consciousness remains unchanged. Recognizing delirium involves noting inattention plus cognitive disturbances that change over a short period and are linked to an identifiable medical factor such as infection, medication effects, or metabolic derangements.