The symptoms of chronic lung disease may appear as early as 3 days after a baby is born. Usually chronic lung disease develops while the newborn is still in the hospital.

Symptoms of difficulty breathing can include:

• Grunting or rapid breathing.
• Flaring nostrils.
• Using the neck, chest, and abdominal muscles to breathe, causing a "sucking in" between or under the ribs (retractions).
• Wheezing (a high-pitched sound when breathing).
• Tiring during and after feeding.
• Having pale, gray, or blotchy skin, especially on the tongue, lips, earlobes, and nail beds.

Infants who have chronic lung disease often need to stay in the hospital for several weeks to months because they need extra oxygen. Some may require oxygen for a while after they go home.

Usually, infants with chronic lung disease have less trouble breathing by early childhood. However, many teens and young adults who had chronic lung disease as newborns have mildly decreased lung function; they may tire easily or notice they are short of breath during exercise. Many children develop symptoms that are similar to those of asthma in early childhood. These symptoms may improve as the child grows. A few children have moderate to severe breathing problems, including difficulty breathing when they are resting.

Infants who have chronic lung disease may develop complications, including:

• Respiratory infections that are often caused by respiratory syncytial virus (RSV).
• Narrowing of the airway (laryngotracheal stenosis).
• Collapse of the airway (tracheomalacia).