is it bad to sleep with WET HAIR?

It makes it more difficult to sleep and can damage hair but apart from that there aren't any health issues. Apart from your hair might look like a huge bush when you wake up!

Its bad and your momma knows it cos she has to wash your pillow case and it'll definitely stink it up! Anyways your hair is at its weakest when it is wet. Leave it to dry before you sleep otherwise it'll stay damp, start to smell and god knows... it might get brittle

It is not bad to sleep with wet hairs but its not good for ones health as one could have a headache the very next day if u get up or in cold weather you could have flu or something like that.

I'll get headache the next day if I don't dry my hair thoroughly before I sleep. It started when I was in my twenties. I don't know the scientific reason behind but according to traditional chinese medicine practitioner, we have pores in our skin and the wet hair will cause 'wind/rheumatism' to develop in our scalp over the night.