Rheumatoid Arthritis?

[Black]

FYI your overall condition may be chronic, but you can get your middle fingers to stop aching if you lay off them for a while.
Assuming you're talking about the last joints towards the end of your fingers-- you can try wearing Oval 8 splints on them for a while., or whenever they bother you.

http://www.amazon.com/Oval-8-Finger-Spli..._hpc_img_y
http://www.amazon.com/Oval-8-Finger-Spli...hpc_text_z