A thorough medical history and physical exam by a physician is necessary for the proper diagnosis of bunions and other foot conditions. X-rays can help confirm the diagnosis by showing the bone displacement, joint swelling, and, in some cases, the overgrowth of bone that characterizes bunions. Doctors also will consider the possibility that the joint pain is caused by or complicated by: Arthritis, which causes destruction of the cartilage of the joint Gout, which causes the accumulation of uric acid crystals in the joint Tiny fractures of a bone in the foot or stress fractures Infection Your doctor may order additional tests to rule out these possibilities.