 245px|right|thumb|hallux valgus. a hallux abducto valgus deformity, commonly called a bunion, is a deformity characterized by lateral deviation of the great toe, often erroneously described as an enlargement of bone or tissue around the joint at the head of the big toe. there is disagreement among medical professionals about the cause of bunions; some see them as primarily caused by the long-term use of shoes, particularly tight-fitting shoes with pointed toes, while others believe that the problem stems from genetic factors that are exacerbated by shoe use. bunions occur when pressure is applied to the side of the big toe (hallux) forcing it inwards towards, and sometimes under or over, the other toes (angulation). as pressure is applied, the tissues surrounding the joint may become swollen and tender. in a survey of people from cultures that do not wear shoes, no cases of bunions were found, lending credence to the hypothesis that bunions are caused by ill-fitting shoes. the bump itself is partly due to the swollen bursal sac or an osseous (bony) anomaly on the metatarsophalangeal joint. the larger part of the bump is a normal part of the head of the first metatarsal bone that has tilted sideways to stick out at its top. == definition == the term "hallux valgus" or "hallux abducto-valgus" are the most commonly used medical terms associated with a bunion anomaly, where "hallux" refers to the great toe, "valgus" refers to the abnormal angulation of the great toe commonly associated with bunion anomalies, and "abductus/-o" refers to the abnormal drifting or inward leaning of the great toe towards the second toe, which is also commonly associated with bunions. it is important to state that "hallux abducto" refers to the motion the great toe moves away from the body's midline. deformities of the lower extremity are usually named in accordance to the body's midline, or the line bisecting the body longitudinally into two halves. in more severe cases, the hallux continuing in the abductus fashion eventually either overlaps or underlaps subsequent lesser (small) toes especially the second (adjacent toe). == signs and symptoms == the sympto
Foot_diseases Skeletal_disorders