Commonly called “funnel chest,” pectus excavatum is a depression caused when the sternum (breastbone) is abnormally pushed inward. The depression in the chest is due to abnormal growth of the cartilage that attaches the sternum to the ribs.  

Because of the deep depression, the abdomen often sticks out and gives the appearance of a potbelly in younger children. If both sides of the breastbone are depressed in an equal fashion, the defect will appear symmetrical. However, in many cases, the chest wall appears asymmetric with one side being wider.   

Pectus excavatum occurs in one in 500 to 1,000 children. It may be minimal, with only slight depression of the chest or it may be quite severe, causing compression of the heart and lungs and altering their functioning. The abnormality increases with age and often worsens during the growth spurts that occur during late childhood and adolescence. It usually stabilizes after skeletal growth is complete.