I have a localized spot on the top of my head, that is really sore. It started a couple days ago, and has since got larger and more sore. It typically only hurts when I make certain facial expressions that tightens my scalp, touch it, or move my hair in that area in any way. It's almost like it bruised, and sometimes feels like it irritated even when I'm not bothering it. I don't have any discoloration on my scalp, no bumps, nothing unusual. I haven't hit my head, I don't wear my hair up (my hair is short).. I can't think of anything that could be causing this. Should I see my doctor about this? Could it be something serious?