What causes a hard bump on the side of a finger?

Answer by  oldmom (716)

While there certainly could be exceptions, most hard bumps on sides of fingers can be traced to where your pen rests when you are writing.

Answer by  drJ (841)

A hard bump could be caused by a thickening of either skin (a callous) or bone (a bone spur). Both are caused by repetitive friction to the area. You can treat callouses by filing them down and moisturizing, but a bone spur must be corrected surgically.

Answer by  ToralDwivedi (606)

Due to constant contact with something like a pen, rod or any object particular for your profession, if held constantly in a fixed position, causes thickening of the skin where the object is in constant contact. Pens often cause thickening of upper middle finger as a result of constant contact.

Answer by  John (9008)

This could be a lot of different things. It could be a wart, which can be removed with an over-the-counter wart remover. It could also be a callous, which is hardened skin that forms on an area that is frequently used. Another possibility is a kelote, which is a form of scar. None of these is dangerous.