It is common for three-year-olds to have chicken breasts, so don't worry. With the increase of age, chicken breasts will gradually fade. At the same time, chicken breasts can also be treated by correction, which needs to be carried out according to the patient's height and weight and the child's physical development. Mild chicken breast is very common in daily life. The key factor is that if the child's nutritional status is poor and the vitamin D or calcium content is insufficient, it will affect the growth and development, leading to the emergence of chicken breasts. Generally mild chicken breast will gradually disappear with the growth of the body. Supplementing calcium and vitamin D and strengthening physical exercise, such as chest-expanding exercise, push-ups and head-raising, can accelerate the correction of deformity.