Abnormal diminished volition Lethargy Torpor Slowness Languor Dullness Inaction HP:0001254 Apathy and lethargy may co-occur. Lethargy A state of fatigue, either physical or mental slowness and sluggishness, with difficulties in initiating or performing simple tasks. Distinguished from apathy which implies indifference and a lack of desire or interest in the task. A person with lethargy may have the desire, but not the energy to engage in personal or socially relevant tasks. SNOMEDCT_US:214264003 Inactivity UMLS:C0023380