What Causes Headache?

I am a 19 year old girl and about 4 days ago I randomly got a sudden horrible headache and it went away with some medicine. Ever since then I have continued to have a headache, but they are not bad at all just normal ones. Then a few days ago my scalp started to itch too and my voice randomly became hoarse then went away in an hour. I don't know what is going on and I would like to know. Could it be anything serious? Or am I just looking into it too much?