Every girl has been told (at least once in her life) that going to bed with wet hair is "bad for your hair" - but has anyone ever stopped to ask why it's so bad?
Well science has finally come to the party and proved that yes, it is infact bad for your hair.
The team over at MIC have revealed what exactly happens when you go to sleep with wet hair... and it's not pretty.
Dermatologist Jessica Krant says, "sleeping with wet hair doesn't do any particular damage to the actual shafts themselves, but it does make it more likely your hair will be flat, frizzy or generally dull-looking when you wake up."
But wait, there's more...
"Each hair shaft is almost 'like roof shingles' that stand up in one direction. However, when your hair is blowdried with gentle smoothing they lie flat (as long as it doesn't overheat them, of course)," Jessica added.
"When you sleep with wet hair, your cuticles end up lying in different angles, thereby reducing the reflective shine and seal of any given shaft and making it seem dirtier."