I have a bump on my foot, too; it is a ganglion, a non-malignant growth (usually). Research says they start in weak, stressed spots sometimes, usually near the ankle. Mine is right where a seam of my athletic shoe crosses the foot; it probably started there because I always wear the same shoes everyday all day. Mine started about 10 years ago, and has grown a bit more and more each year. It started out that it occasionally hurt but now it hurts frequently when pressed (putting on shoes) or when the tissues shift (upon standing) or shifting positions in bed. I want to have it removed next summer. I have had it x-rayed and had the doctor give me an opinion that it was pretty firm and wasn't the type that could be aspirated (liquid drawn out of the bump).
have it examined by a podiatrist. unfortunately, i can't see the bump...so it is difficult for me to assess and recommend treatment.
if the bump is growing and hurting, it needs to be examined to rule out malignancies.
if it hurts, it should be removed.