Index Finger Joint Pain

[JJT247]

Hello talkbass, I am 16 years old (so i dont think i have arthritis) and all of my fingers feel perfect while playing bass except for my left index finger (which i fret with).

However, It does not hurt at any other time then when I have to stretch it to do whole step patterns for example. No other fingers have this problem and it hurts in the middle part of the index finger (where you bend it).

Also, this pain has been here for about a year now so it isnt just sore.
What could this be?

[otherclef]

Can u cause the pain pressing the finger against a table or a wall... if so then stop playing for a while and see if the pain goes away. Then you 'll know its the playing and go from there.