I have a strange swelling on my left leg, just about the knee that goes all around the side of my thigh. It is not painful, but my leg does feel weird. Can't explain how it feels, just weird. It is not red, or discolored in any way, just swollen in this one area. I have not injured it, and it does not appear to be a bite of any kind. The area swollen is about the size of a softball. It is not a hard lump, just swollen. I am very concerned, but don't want to go to the emergency room if it is nothing. Any ideas as to what this could be? Does it sound like anything serious?