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 lower ribs can stick out and give the appearance of a potbelly in younger children. If both sides of the breastbone are depressed in an equal fashion, the defect will look balanced. However, in many cases the chest wall appears unequal, with one side being wider. 

Pectus excavatum occurs in one in 300-400 children. It may be minimal, with only slight depression of the chest, or it may be quite severe.  When severe, it pushes down on the heart and lungs and makes it hard for them to work properly. The abnormality often 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.