This is a very good question that can inform a lot of people. Thanks for asking it. So, Rheumatoid arthritis, you probably know, is an autoimmune disorder. It causes a constant inflammatory response that damages the lining of joints causing swelling and it is painful, can contribute to bone erosion and deformity. It can damage other organs of the body too.
Who gets it and why is a bit unknown but it definitely has a genetic component. Also those who were exposed to viruses or bacteria early in life may have an increased risk. DNA would probably be to blame for why women get it more than men. It's also a progressive disease so perhaps younger people don't always show the signs of it and they don't see it until they are older (as over 4o is when it is diagnosed more). for those who are diagnosed younger, perhaps it progressed sooner.
dmards are the class of drugs that treat rheumatoid arthritis and they can have a good effect from those who suffer from it.
Why do you ask this question? Someone you know being diagnosed?