If I pay off adverse accounts on my credit report..?

will my score go up? Or will it go down. Or will it even make a difference? I have about four adverse accounts on my report. Three of them are medical bills and one is something I don't recognize. They total no more than a thousand dollars and I am wondering if I pay them, will they be removed? Will this just add more time on my report. I just want my score to go up and wonder is I pay these off if that will help? Thanks.