It's not that straightforward...
We've all grown up with the same warnings. Don't leave the house with wet hair; and don't go to bed straight after washing it. But, is sleeping with wet hair really that bad for you?
Well, yes and no. Yes, it's bad for you, but not for the reasons you think.
No doubt you're under the assumption that going to sleep with wet hair can lead to having a cold. However, the common cold is caught by a virus, so it's unlikely that going to bed with wet hair in cold temperatures will actually cause a cold. Although there's some evidence to suggest that it can make you more susceptible to the virus, in terms of whether it directly causes it, the answer is no.
In fact, the real reason why it's bad for you actually comes down to the health of your hair. When your hair is wet, it's in a 'compromised' state. This is why you need to take extra care of your hair straight after you've washed it. Just as you shouldn't tug or pull your hair with a comb or brush while it's wet, you also shouldn't be tossing and turning in bed. Each time you do, you risk over stretching your hair shaft, which can lead to damage.
If you can't keep your eyes open long enough to completely blow dry your hair before bed, you should at least towel dry it before letting your head hit the pillow. And if you're in the habit of tying your hair into a bun while it's wet before you go to sleep, don't. Yes, you can wake up with amazing wavy hairstyles, but it can also lead to serious damage. Not only will your hair get tugged as you turn in your sleep, it will also get pinched by your hair tie and in most cases be tugged to the point of falling out.
But, if you refuse to change your habit of sleeping with wet hair, invest in a silk pillowcase. The smaller fibres will create less drag on your hair when you move.
