Rickets and rib flaring are different; rib flaring can be considered a symptom of rickets. Rickets is caused by a deficiency of vitamin D in infants and children, leading to abnormal metabolism of calcium and phosphorus, which results in incomplete calcification and softening of the bones, thereby causing skeletal deformities. Rickets can be divided into initial, active, recovery, and sequelae stages. During the active stage of rickets, skeletal deformities such as softened skull, "ping pong" head, square skull, rib flaring, pigeon chest, funnel chest, X-shaped legs, and O-shaped legs are prone to occur.