Navi's left arm has developed a lump or some swelling right above the carpal bone that is hard, doesn't move when you push on it and it's NOT painful.
Several months ago after a walk she had the same swelling accompanied by a mild limp that lasted that evening and was gone by the next day. The swelling went away pretty quickly. It came back a few days ago and was double the size that it is in this photo, but this time she didn't have a limp and isn't in any kind of pain at all. The next day it has gone down to this size and hasn't changed since.
What might it be?
by sk Ki
, on Flickr