After a cold day I took my sweater off and noticed my right arm was swelled almost twice the size of my other arm. I immediately freaked out and asked my parents, and they didn't have an answer either. My sister is a nurse and checked it out, but I don't know. There's no brusies, bites, pain, or anything. My arm is just really swollen, plus I've never been allergic to anything so I doubt that. But I do have a weight training class and last week I worked myself really hard, any ideas??