Tossing and turning causes breakage due to friction from standard cotton...

https://shanestue668.yousher.com/what-should-i-do-tonight-to-wake-up-with-less-frizz-tomorrow

Tossing and turning causes breakage due to friction from standard cotton pillowcases. Switching to silk helps, but you can also try a loose braid or a silk bonnet to keep your ends protected while you sleep