system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5 If skin is constantly renewing itself, why do blemishes remain?
gpt
The outer layers of the skin are formed by the cast-off remnants of the deeper layers. Blemishes exist in the underlying layers of the skin, where the cells are dividing to replace lost ones, and those get expressed on the outer layers as the cells surface and slough off.