A bunion is a deformity that usually occurs at the end of one of the five long bones (the metatarsal bones) that extend from the arch of the foot and connect to the toes. Most often bunions develop in the first metatarsal bone (the one that attaches to the big toe). A bunion may also develop in the bone that joins the little toe to the foot (the fifth metatarsal bone), in which case it is known as either a bunionette or a tailor's bunion.
A bunion typically develops in the following way:
- The big toe or the fifth ("pinky") toe is forced in toward the other toes, causing the head of the metatarsal bone to jut out and rub against the side of the shoe.
- A bunion begins to form when the big or little toe is forced in toward the rest of the toes, causing the head of the metatarsal bone to jut out and rub against the side of the shoe.
- The underlying tissue becomes inflamed, and a painful bump forms.
- As this bony growth develops, a bunion is formed as the big toe is forced to grow at an increasing angle toward the rest of the toes. One important bunion deformity, hallux valgus, causes the bone and joint of the big toe to shift and grow inward, so that the second toe crosses over it.
People born with abnormal bones in their feet are more likely to form a bunion. In addition, wearing narrow-toed, high-heeled shoes, which put enormous pressure on the front of the foot, may also lead to a bunion formation. The condition may become painful as extra bone and a fluid-filled sac grow at the base of the big toe.
Flat feet, gout, arthritis, and occupations (such as ballet) that place undue stress on the feet can also increase the risk for bunions.
Shoes and Protective Pads. Pressure and pain from bunions and bunionettes can be relieved by wearing appropriate shoes, such as the following:
- Soft, wide, low-heeled leather shoes that lace up
- Athletic shoes with soft toe boxes
- Open shoes or sandals with straps that don't touch the irritated area
A thick doughnut-shaped, moleskin pad can protect the protrusion. In some cases, an orthotic can help redistribute weight and take pressure off the bunion. Nonsteroidal anti-inflammatory drugs (NSAIDs) or corticosteroid injections may offer some pain relief.
Review Date: 01/30/2011
Reviewed By: Harvey Simon, MD, Editor-in-Chief, Associate Professor of Medicine, Harvard Medical School; Physician, Massachusetts General Hospital. Also reviewed by David Zieve, MD, MHA, Medical Director, A.D.A.M., Inc.