Congenital diaphragmatic hernia (CDH) is a congenital malformation (birth defect) of the diaphragm. The most common type of CDH is a Bochdalek hernia

Bochdalek hernia

A Bochdalek hernia is one of two forms of a congenital diaphragmatic hernia, the other form being Morgagni's hernia. A Bochdalek hernia is a congenital abnormality in which an opening exists in the infant’s diaphragm, allowing normally intra-abdominal organs to protrude into the thoracic cavity...

; other types include Morgagni's hernia, diaphragm eventration and central tendon defects of the diaphragm. Malformation of the diaphragm allows the abdominal

Abdomen

In vertebrates such as mammals the abdomen constitutes the part of the body between the thorax and pelvis. The region enclosed by the abdomen is termed the abdominal cavity...

 organs to push into the proper lung

Lung

The lung is the essential respiration organ in many air-breathing animals, including most tetrapods, a few fish and a few snails. In mammals and the more complex life forms, the two lungs are located near the backbone on either side of the heart...

 formation.

CDH is a life-threatening pathology in infants, and a major cause of death due to two complications: pulmonary hypoplasia

Pulmonary hypoplasia

Pulmonary hypoplasia is incomplete development of the lungs, resulting in an abnormally low number or size of bronchopulmonary segments or alveoli. A congenital malformation, it most often occurs secondary to other fetal abnormalities that interfere with normal development of the lungs...

 and pulmonary hypertension

Pulmonary hypertension

In medicine, pulmonary hypertension is an increase in blood pressure in the pulmonary artery, pulmonary vein, or pulmonary capillaries, together known as the lung vasculature, leading to shortness of breath, dizziness, fainting, and other symptoms, all of which are exacerbated by exertion...

.