Tracheomalacia occurs when the cartilage in the windpipe, or trachea, has not developed the way it should. Instead of being rigid or firm, the walls of the trachea are floppy. This can make it hard to breathe because the cartilage cannot keep the windpipe fully open while breathing. It may collapse when exhaling.

Tracheomalacia can be mild enough to not need any treatment. It can also be moderate or severe (life-threatening). Most children with this condition will either outgrow it by the time they turn 2 or have symptoms that are not severe enough to need surgery.