hi i have a lump on the joint from my middle finger to my hand. itz been growing very slowly over the past months

Some causes of finger joint lump.

Osteoarthritis, the most common form of arthritis, often affects the hands. Gout also causes lumps in the fingers. Rheumatoid arthritis causes joint (knuckles) lumps. Soft tissue swelling as a result of blisters and calluses. A rare disease called histiocytosis may also cause lumps to appear in the distal row of finger joints.

Better have a doctor check it out for a correct diagnosis.