Description: If you've been injured while exercising or playing a sport, the first thing you should do is to quit the activity and evaluate the injury.

The National Institute of Arthritis and Musculoskeletal and Skin Diseases says you should see a doctor if the injury is extremely painful, is causing significant swelling, or if you can't put any weight on the injured area. You should also see a doctor if you've aggravated an old injury that's become painful or swollen.

If you're treating the injury at home, begin the RICE method as quickly as possible and follow it for at least the next 48 hours. RICE stands for: Rest, Ice, Compression, and Elevation. In short, don't exercise or strain the area, and keep it iced for 20 minutes at a time, four to eight times per day. And, if possible, keep the area wrapped and elevated to a level above the heart.