Lethargy is best defined as which of the following?

• A. Drowsy state with brief responsiveness followed by return to sleep
• B. Complete unresponsiveness to external stimuli
• C. Reduced alertness with slow responses and confusion
• D. State requiring vigorous stimulation to elicit response

Answer: (A)

Lethargy is a decrease in arousal where a person is drowsy and not fully alert but can be awakened with mild stimulation and will respond briefly before drifting back to sleep. This pattern—being sleepy, showing only limited responsiveness, and then returning to sleep—is what defines lethargy. It sits between full alertness and deeper impairment. It’s different from complete unresponsiveness (coma) or from states where you need strong stimulation to elicit any response (stupor) or where alertness is only mildly blunted with more noticeable confusion (obtunded). So the description of a drowsy state with brief responsiveness followed by return to sleep best matches lethargy.