I think i have rheumatoid arthritis. the ends of my fingers hurt so bad sometimes.

Probably not: Pain in the last joint of your fingeris typical of osteoarthritis (o.A.) which would be more common at your age. Sometimes people even get little lumps at that last finger joint called heberdeen's nodes. R.A. Tends to cause more soft tissue swelling with inflammation; the joints might actuaaly look a little red and be tender or warm. O.A. Can cause stiffness particularly after rest.

Osteoarthritis: It's more likely to be osteoarthritis when the ends of the fingers are involved.