Swelling

One day last week I came home from work, took off my shoes and noticed my left foot was swollen. I thought it was weird because I haven't injured it and I don't spend all day on my feet. Plus, it was just one foot that was swollen. I layed down for a bit but by the end of the night it was still swollen. It didn't hurt or anything but I wondered what was happening. I called my mother-in-law (she's a nurse) and after evaluating the options told me I should probably go to the instacare because it might be a blood clot. The doctor at the instacare examined it and checked my heart and lungs and said that nothing was wrong. He said sometimes it can happen if your heart has been working hard for awhile, then suddenly stops. This makes sense since I was doing P90X faithfully, then finished. He said that his wife's foot has been swollen for years, and they cannot find out why. I guess it's just a crazy incident! The next morning my foot was back to normal, huge sigh of relief, but when I got home from work it was swollen again! It happened the next day as well, but hasn't happened since. Maybe it was my diet or something, but it was weird. See for yourself.