Sounds like a ganglion cyst. Check it out. Not dangerous, just annoying.
I Have A Bump Under The Skin On My Right Hand Third (middle) Finger. It Hurts Especially When Touched. What Can It Be? I Can't Make A Fist. My Hands Are Too Swollen.
The bump with pain on your finger can be due to contact allergy. Note all things which you touch during the day including office and home. One type bump which usually occur on finger has no reason and has no treatment. It continue to come and go. Visit a dermatologist for differential diagnosis.