What could be wrong with my finger?

About a month ago I was weed eating my yard, and ever since that day, the middle knuckle on my middle finger on my left hand aches ( I am left handed). What could be an explanation of the problem or a solution. Should I be worried?

Please, no “middle finger” jokes…ha ha


How did they taste?

Seriously, chronic pain lasting a month? Definately see a doctor.