What Causes a Bunion?

Bunions are relatively common foot problems that can affect anyone. They seem to be more common in females and usually occur in both feet [1,2]. The symptoms vary from one person to the next. Some people find it difficult to walk all the time, while others only experience pain in certain shoes. These symptoms may vary depending on the cause of the bunion.

Sometimes the cause of the bunion is due to genetics. A person's foot structure is passed down from one generation to the next. We inherit the shape of our foot from our parents [3]. Certain foot types often lead to problems in the way a person walks. Therefore, although the bunion deformity does seem to run in families, it is actually the foot type that is hereditary and it is the foot type that can lead to the development of a bunion. That is why it often seems that the bunion worsens as we age. If your genes predetermine you to develop a bunion, nothing can prevent them, but you may be able to slow their progression.

Those who have flat feet (low arches) seem more prone to develop bunions than people with higher arches. That is not to say all people with flat feet acquire bunions or those who have high arches will not be afflicted. Another cause of bunions can be increased flexibility of the feet. This can be a result of many factors including genetics, foot type (flat feet), or pregnancy. During pregnancy, hormones are released that allow the ligaments in the body to become relaxed. It is not uncommon for the arches in the feet to become flattened and influence the development of bunions.

In addition, improper fitting shoes or shoes with narrow toes may push your big toe outward toward the second toe (figure 2). After years of this pressure, the deformity may accelerate by gradually and permanently pushing the big toe toward the second toe.

Finally, injury to the joint can hasten the progression of a bunion. Different types of arthritis can also predispose a bunion formation. Gout and rheumatoid arthritis are two examples of arthritis that may lead to a painful bunion.