It occurs when the big toe points toward the second toe. This causes the appearance of a ridge on the outer edge of the finger.
Bunions are more common in women and can sometimes run in families. People born with abnormal bones in their feet are more likely to form a bunion.
Also, the use of close-toed shoes and high heels can lead to the development of a bunion.
The condition may become painful as the bump gets worse and the extra bone and a fluid-filled sac grow at the base of the big toe.