It's a sad truth for those with thicker, slow-drying locks: Sleeping with wet hair isn’t the best idea. When your strands are wet, your hair and scalp are actually more vulnerable to damage. A few specific risks include, “unwanted bacteria, fungal infections, skin irritation, itchiness, dryness, redness, and dandruff," hairstylist Miko Branch, co-founder of hair care brand Miss Jessie's, previously told mbg.
What’s more, sleeping with wet hair may lead to increased tangling and split ends. So if your hair tends to knot easily or frizz at the tips, you may want to make sure your locks are completely dry before bed or opt for morning showers instead.
If you can give your hair more time to air-dry (i.e. shower earlier in the evening) that’ll do the trick. Otherwise, opt for a quick blow-dry to get most of the excess water out. Your hair doesn’t need to be perfectly dry, just a quick blow will do. Just make sure to use a low heat setting—as we mentioned, frequent heat styling is a recipe for weakened strands.
However, if you don't think your hair is that damaged (by heat, bleach, etc.), then you may be A-OK sleeping on damp strands. Just pay attention to how your hair and scalp feels and looks (yes, actually look at your scalp in the mirror) and perhaps invest in a silk or satin pillowcase to minimize friction. If you aren’t experiencing any of the problems Branch mentioned, that’s one sign you may be able to keep sleeping on wet hair if you want to. After all, not everyone is a morning shower type of person.