Health Topics A-Z

What Is a Bunion?

A bunion is an unnatural bony hump that forms at the base of the big toe when that toe deviates toward the other toes. When this occurs, the base of the big toe pushes outward, forming a bunion.

If this happens on the little toe, it's called a bunionette.

Because a bunion occurs at the joint where the toe bends in normal walking, your entire body weight rests on it at each step. It can be extremely painful. It is also vulnerable to excess pressure and friction from shoes and can lead to the development of calluses.

What Causes It?

oot problems typically develop in early adulthood. They get worse as the foot spreads with aging. For many people, bunions run in the family. They may be just one of several problems due to weak or poor foot structure. Bunions sometimes develop with arthritis. In people with leg length discrepancies, bunions can form in the longer leg.

Women are especially prone to developing bunions. Years of wearing tight, poorly fitting shoes — especially high-heeled, pointed shoes — can bring on bunions. Such shoes push the foot bones gradually into an unnatural shape. Women also have looser ligaments which makes them more likely to develop bunions.