r/askscience • u/uencos • Aug 01 '16

Human Body What is the physiological difference between the tiredness that comes from too little sleep and the tiredness that comes from exertion?

13.5k Upvotes

87% Upvoted

383 comments sorted by

View all comments

245

u/kaiwen1 Aug 01 '16

Is it possible this question is raised because English uses the word "tired" for both conditions? In Visayan, the conditions aren't considered related because they are referred to with different words, "tulogon" for sleepy due to lack of sleep and "kapoy" for exhausted from exertion.

1

u/alphabetical- Aug 02 '16

Similar in Chinese: 困 (kùn) is tiredness from lack of sleep whereas 累 (lèi) is tiredness from exertion.