Bunions. Coloured X-ray of an elderly woman's deformed inward-turning toes due to bunions (red, lower centre). This deformity (hallux valgus) is caused by wearing ill-fitting shoes, such as pointed high- heels. The rubbing of the shoes often causes a bunion (swelling of the large toe joint) to form. In the case of a bunion being large enough to impair toe movement, surgery may be required to straighten the joint.