Quick Answer: A bunion, also known as hallux valgus, is an outward deformity of the foot's metatarsophalangeal joint which connects the big toe to the foot. The rear tarsametatarsal joint that holds the metatarsal bone in a straight-ahead position weakens, and the metatarsal moves outward and rotates 90 degrees, bringing the sesamoids up against the adjacent toe. This results in the head of the metatarsal bulging outward while the big toe bends inward toward the other toes. The joint often becomes red and painful due to rubbing in a cramped shoe. The onset of bunions is typically gradual. Joint complications may include bursitis or arthritis. A similar condition of the little toe is referred to as a tailor's bunion or bunionette. Treatment may include proper shoes, orthotics, or NSAIDs. If this is not effective for improving symptoms, surgery may be performed. Since 2020, many new and highly effective surgical techniques for bunion correction have been developed.