Bunions are visible bumps on the side of the big toe. The big toe consists of two joints, and the largest of the two is the meta-tarsophalangeal joint (MTP). Bunions can form when the bones that make up the MTP joint get out of alignment, the phalanx bones of the big toe start pointing towards the second toe and the MTP joint gets larger and starts protruding. This can often lead to inflammation and swelling, which in turn leads to difficulty walking over time.
Bunions are often caused by an inherited faulty structure of the foot. Bunions themselves are not inherited, but certain foot types are more likely to develop them. Having an inflammatory condition like rheumatoid arthritis may also cause bunions. Narrow shoes which lead to toe crowding don’t cause bunions, but they can speed up the process and make the symptoms worse.
Pressure on the big toe due to uneven weight distribution can also cause the big toe to point towards the second toe. Bunions are progressive, and usually develop slowly over time. The bigger they get, the more painful they can become. Pressure from the big toe may eventually push the second toe out of alignment and cause issues with the smaller toes as well.