A bunion is a foot deformity that occurs when the bones in your big toe are pushed out of their typical position. This type of deformity develops over time as pressure forces the tip of your big toe to lean toward the second toe.
As the tip of the toe bends, the joint at the base of the toe is forced to stick out. This creates the classic sign of a bunion: a bump on the side of your foot.
When your bunion goes untreated, the structure of your toe changes and the joint becomes inflamed. You can also develop bursitis, an inflammation of fluid-filled sacs in the joint.