text: my knuckle is swollen and very painfull. i didn't hit it or jam it. any reason you know of? i play the bass, but no more than i have for the past 5 years, and it swelled overnight. i'm only 25. arthritis??? i can't bend it all the way. you should go see a doctor.  it could be many things, but there is a chance you have rheumatoid arthritis.  it is characterized by morning stiffnes in the joints, along with pain and inflammation.  i am 23, and one year ago i started off with similar symptoms in one finger, then i started getting it in the others.  i went to the doctor, was diagnosed with ra, and started treatment.  although your problem may not be ra (i hope it's not... it's a serious, debilitating disease but their are some great treatments now), you should see a doctor asap.  make sure you demand a blood test so they can check your inflammation levels etc.  if you do have ra, the sooner you start treatment the better.  it took me about 9 months to regain the use of my hands, and i'm lucky that i did.  it can cause permanent damage, but the newer meds can help slow down the damage.  go asap, because i'm sure your hands are very valuable to you as a musician, and if there is something serious you need early treatment.  also please visit wwww.arthritis.org for some backround on ra before your visit to the doctor so you can be more informed and ask the right questions so they can give you a proper diagnosis.  if it does turn out to be ra, push for early treatment, and visit the discussion boards at ra connect on the arthritis.org site.  there you will find lots of people who are happy to give you support or info.  please remember that there is no way to get a diagnosis except from your doctor, and there are many other, far less serious, things that could be causing your problem.  however, since it is similar to my situation i urge you to see a doctor in case it really is serious.