I have a bump under the skin on my left foot that is painful when touched or when I walk.

Dear Beba
The "bump" under your foot can be a number of things, such as a callus, corn, wart, foreign body, or melanoma. Unfortunately, the best way to find out what the "bump" is to go to either a podiatrist or dermatologist in order to make an accurate diagnosis.

Good-luck and thank-you for contacting foot.com,
SBarlizo, DPM, C Ped
foot.com expert