The term is used to refer to the pathological bump on the side of the great toe joint. The bump is partly due to the swollen bursal sac and/or an osseous (bony) anomaly on the mesophalangeal joint (where the first metatarsal bone and hallux meet). The larger part of the bump is a normal part of the head of first metatarsal bone that has tilted sideways to stick out at its top.

The symptoms of bunions include irritated skin around the bunion, pain when walking, joint redness and pain, and possible shift of the big toe toward the other toes. Blisters may form more easily around the site of the bunion as well.

Having bunions can also make it harder to find shoes that fit properly; bunions may force a person to have to buy a larger size shoe to accommodate the width the bunion creates. When bunion deformity becomes severe enough, the foot can hurt in different places even without the constriction of shoes because it then becomes a mechanical function problem of the forefoot.

Bunions may be treated conservatively with changes in shoe gear, different orthotics (accommodative padding and shielding), rest, ice, and medications. These sorts of treatments address symptoms more than they correct the actual deformity. Surgery, by an orthopedic surgeon or a podiatrist, may be necessary if discomfort is severe enough or when correction of the deformity is desired.