What sort of problem is arm swelling?

Arm swelling: Arm swelling is a relatively uncommon problem. The most common and usually obvious causes are related to trauma--falls, contusions, etc. Other rare but serious causes include a blood clot in the axillary vein (often in people who use crutches or lift heavy weights), or a rare late complication of an injury where the nerves are functioning wrong (reflex sympathetic dystrophy).