The majority of pectus excavatum cases encountered clinically are congenital thoracic deformities, which means the sternum in the middle of the chest is indented inward and backward. This inward and backward indentation can compress the lungs and the heart, especially in severe cases of pectus excavatum, causing significant compression to the lungs and heart. It prevents the heart from fully expanding, and might even push the entire heart into the left chest cavity, also preventing the lungs from effectively expanding. Therefore, children with this condition tend to have weaker constitutions, are prone to colds, and their ability to engage in physical activities like running is not as good as other children. Pectus excavatum generally affects the development of children, especially in severe cases. Mild pectus excavatum involves only a slight indentation and does not severely compress the heart, and children with such a condition can still gain weight if their nutrition is adequate. However, in severe cases of pectus excavatum, besides impacting the heart and lungs, it can also affect the patient's personality, self-confidence, and social interactions, potentially leading to insecurity, depression, and even suicidal tendencies.