Eli5 – Why does lack of sleep give you bags under your eyes?

Question

What’s the purpose here?

In: 17

Answer 1

Lack of sleep weakens your body’s ability to pump fluids around in general, which means we tend to swell a bit as pools of fluid build up. It’s just that under our eyes is extremely thin, tight skin so any minor changes in thickness or fluid retention is really obvious and noticeable. It’s not that there is some special purpose or reason why we get bags specifically under our eyes.