A bunion is a deformity of the foot in which the 1st metatarsal is turned inward and the bunion is excessively tilted to the outside. There are many reasons for bunion, such as bad shoe habits, primary metatarsal inversion deformity, aging, rheumatoid arthritis, etc. The most common reasons for bunion are the following 1. Bad footwear habits: If you wear pointed shoes and high heels for a long time, the forefoot will be squeezed by the shoes, and the metatarsophalangeal joints will be easily shifted inward due to excessive pressure on the 1st metatarsal bone, which will be manifested as a bunion. 2. Primary metatarsal inversion deformity: Due to genetic factors, the shape of the medial cuneiform bone is specialized, which makes the 1st metatarsal invert, resulting in secondary bunion deformity, which is mostly seen in adolescents with bunion. 3. Ageing: With age, the flexibility of the ligaments in the foot weakens, and the extensor-flexor muscles are balanced, resulting in poor foot stability, which can easily lead to bunion deformity. 4. Rheumatoid arthritis: Rheumatoid arthritis is a systemic autoimmune disease in which the synovial membrane of the joints becomes inflamed and the normal structure of the metatarsophalangeal joints is damaged, resulting in outward semi-dislocation of the metatarsophalangeal joints and the appearance of bunions. In addition to the above, bunions can also be caused by flat feet and neuromuscular disorders. If a bunion occurs, it is advisable to improve your shoe-wearing habits. If the pain cannot be relieved on its own, you should consult a doctor for a checkup and take appropriate treatment according to the cause of the problem.