My hair gets itchy again soon after I wash it.

I definitely washed my face in the evening, but by the time I go to sleep, it gets so itchy that it's hard to bear.

I try my best not to scratch my head, but before I know it, I find myself scratching it little by little.

As a result, it seems like I have some wounds on my scalp. Did I wash my hair incorrectly?

I don't know why it's so itchy.