Bronchomalacia is a term for weak cartilage in the walls of the bronchial tubes, often occurring in children under a day.

If only the upper airway the trachea is involved it is called tracheomalacia (TM).

Secondary bronchomalacia may occur by extrinsic compression from an enlarged vessel, a vascular ring or a bronchogenic cyst.

Bronchomalacia can best be described as a birth defect of the bronchus in the respiratory tract.

It may also be acquired later in life due to chronic or recurring inflammation resulting from infection or other airway disease.