10 days ago I slipped in tub as I was standing up to get out. Small cut on eyebrow, slight black eye, went to medical at work to ensure not a concussion. Next day realized I had hit my upper arm during the fall and it was very uncomfortable, then hot, brushed very colorful, could not lift brief case with that arm, etc. Now it is still be used but healing, about the size of my open hand. There is a fairly large knot or lump in it, should I be concerned or just live with it?