Chronic lung disease is a condition in which damaged tissue in a newborn baby's lungs causes breathing and health problems. The lungs trap air or collapse, fill with fluid, and produce extra mucus.

Most babies who have chronic lung disease survive, and many outgrow their lung problems.

Chronic lung disease is also known as bronchopulmonary dysplasia (BPD).

What causes chronic lung disease?

Factors that alone or in combination can lead to chronic lung disease include:

    * Being born early (prematurely). Chronic lung disease most commonly occurs in babies who are born before 26 weeks of gestational age and who weigh less than 2.2 lb (998 g). 1 A premature baby's lungs may not be fully developed. This makes the baby likely to develop infections, swelling, and fluid buildup that can lead to chronic lung disease.
    * Injury to the lungs from the forced breathing and high concentrations of oxygen that accompany treatment with a ventilator. Many premature babies need this type of treatment, especially those who develop respiratory distress syndrome.
    * A heart condition that is known as a patent ductus arteriosus.
    * Inherited abnormalities that affect lung development.
    * Fluid in the lungs. Premature babies may be born with fluid in their lungs. Some babies who are born prematurely or at full-term by cesarean section develop fluid buildup in their lungs. Rarely, a newborn breathes meconium into the lungs during delivery. This causes lung irritation and inflammation that damage lung tissue and can lead to chronic lung disease.
    * Infections. Premature babies are more likely to get lung infections, particularly respiratory syncytial virus (RSV).
    * Lack of nourishment. Newborns who are not able to get the proper nutrients, particularly vitamin A, are more likely to develop chronic lung disease.

What are the symptoms?

Symptoms of chronic lung disease may develop as soon as 3 days after birth.

The most common first symptom of chronic lung disease is difficulty breathing. You may notice your newborn:

    * Grunts or breathes rapidly.
    * Flares the nostrils.
    * Uses the neck, chest, and abdominal muscles to breathe. This can look like your baby is "sucking in" air between or under the ribs (retractions).
    * Wheezes, which is a high-pitched sound that occurs with breathing.
    * Tires easily during and after feeding.
    * Has pale, gray, or blotchy skin, especially on the tongue, lips, earlobes, and nail beds.

How is chronic lung disease diagnosed?

There is no one test to diagnose chronic lung disease. A doctor may first suspect it if your baby has difficulty breathing. The diagnosis is confirmed when both of the following are present: 1

    * The baby needs extra oxygen for at least 28 days after birth.
    * At 36 weeks of gestational age, the baby needs more oxygen than is present in ordinary air. Gestational age is the number of weeks and days a baby has developed since the beginning of the pregnancy, or gestation.

A doctor may order other tests to rule out other causes of breathing difficulties. A baby who has been already diagnosed with chronic lung disease may have additional tests to help doctors check for complications.