Each of your feet has 26 bones, 33 joints, and more than 100 tendons, muscles and ligaments. No wonder a lot of things can go wrong. Here are a few common problems: Bunions - hard, painful bumps on the big toe joint Hammer toes - toes that curl downward into a claw-like position Calluses and corns - thickened skin from friction or pressure Plantar warts - warts on the soles of your feet Fallen arches - also called flat feet Ill-fitting shoes often cause these problems. Aging and being overweight also increase your chances of having foot problems.