Best way to describe this is to ask you to put your RIGHT forefinger, onto the knuckle furthest away from your fingernail on your LEFT forefinger.
Now put your right thumb under where your right forefinger is.
Just there I have a pea sized hard lump, which is rather quite painful, any ideas what it is please ?
I've got them on all the joints in my fingers but I still do knitting.
Once they get to a certain pitch they stop hurting.
Might not be that though.
Don't bash it with a book ..that's an old wives remedy for ganglions which are usually on your wrist .
shaneystar is " right on the money" it does sound like a Heberden's Node.
It is usually, but not always associated with osteo- arthritis.
No big deal.........just leave it alone.