A bunion is a bony bump that forms on the joint at the base of your big toe. It occurs when your big toe gets pulled toward the smaller toes and forces the joint at the base of your big toe to stick out. This develops gradually overtime and the skin over the bunion might become red and sore.
Wearing tight, narrow shoes might cause bunions or make them worse. Bunions can also develop as a result of the shape of your foot, a foot deformity or a medical condition, such as arthritis.