A bump in my arm left after bruisinng has gone after a fall what is it?

Healing: I am not sure what or why you are asking. It sounds like you had an injury that resulted in a bruise (which is a blood clot under skin). And it has healed appropriately. What is your concern?

Arm bump: Most likely some residual inflammation and/or left over blood from the hematoma (bruise). I see this all the time. It will eventually go away.