A bunion, known technically as hallux valgus, is a bony bump on the side of the foot at the base of the big toe. Bunions develop slowly as pressure on the joint at the base of the big toe causes the toe to move out of place, leaning inward toward the second toe. Because this joint carries a lot of weight during activities like standing and walking, bunions can cause foot pain, stiffness, redness, and swelling. Calluses may form where the big toe and second toe rub together or on the ball of the foot. Unless they are treated, bunions get worse over time, and it may become difficult to wear regular shoes or walk without pain. Bunions can occur in one or both feet.~In most cases, bunions develop in adulthood. Rarely, children may be born with bunions (known as congenital hallux valgus) or develop them later in childhood (juvenile or adolescent hallux valgus).