I am 59 female, good health, started bootcamp- type intensive fitness sessions a few months ago. about 4 weeks ago. Around that time, I noticed my left arm hurt and itched like crazy, very deep in my left upper underside of my arm. This area of my arm still hurts just to touch it, and a large area (softball size) now shows bruising. Can use arm, lift, work in the yard, etc, but nags me and hurts to touch. Thought I would just give it time, but husband and kids are worried.