Most likely a scar (you can check your journal in the injuries/scars section) - you can get those healed with either the Major Healing spell (I believe) or having a skilled healer (or yourself) heal you with the heal skill.

It could also be a curse or a cursed item.

Ok so i have no injuries or curses according to my journal, i also fully emptied my inverntory and everything i carried and i still had 7 beauty. What else can it be?

Hrm. Have you been making sacrifices at the altars? You might have pissed off a deity somewhere.

No havent been to any altars. Its annoying since now people start off as being suspicious to me rather than netutral. Could it be a bug?

I might be an (bugged) item that you wore briefly then got rid of a while ago that lowered your beauty permanently. But I don't know if there is actually an item that does that...

So possibly a bug.

Heh ok, well i guess i'll spend a point and make it 8 again.

So i went back to the mining town and to the healer there and requested healing, there was an option to heal an attribute and now my beauty i back up to 8 :)

Sounds like it was an untracked scar, somehow. Glad you're well.
He's a damn good healer.