My son has developed a bump on side of his foot after playing a lot of basetball. It is swollen and is red and tender to the touch.

My son has developed a bump on side of his foot after playing a lot of basetball. It is swollen and is red and tender to the touch. He couldn't play his last game due to the pain. He doesn't remember twisting or hurting it.

Hi,
It looks like he may have irritated the tendon that attaches into the fifth metatarsal base. This can occur from wearing shoes that are too narrow and the constant pressure against that part of the foot.
You can wait a while to see if it "calms" down but more than likely you would be smarter to see a podiatrist because if nothing else, you can assume it will occur again next time he plays basketball for any length of time.
Marc Mitnick DPM