Edema left foot

I have not been diagnosed with cancer, but was rather hoping someone might be able to give me a few ideas about the sudden appearance of edema in my left foot and calf.I do have osteoarthritis (mild), which I manage by daily exercise (at least 1 hour), biking, walking, and weight lifting. I have been exercising like this for three years and I have never had a problem. I eat organic foods, and do not eat any white flour or white sugar, eat a lot of raw spinach.   The edema showed up suddenly after two weeks of not exercising due to illness.  There is no numbness in the leg, just the foot, and the foot is swollen so that I cannot see the veins in my foot. I can get it into a shoe, but it's not real comfortable. Th...