A diaphragmatic hernia is a protrusion of the upper part of the stomach through the diaphragm, the dome-shaped muscle that separates the two thoracic and abdominal cavities. This means that part of the stomach is abnormally protruding and into the thoracic cavity. Most cases of diaphragmatic hernia are mild and asymptomatic, but in severe cases, diaphragmatic hernias can be uncomfortable, painful, and can lead to reflux.

The diaphragm is a thin layer of muscle that separates the chest and abdomen. When abdominal organs are present in the chest, it is called a diaphragmatic hernia. Diaphragmatic hernia in adults is an uncommon disease, when it occurs, early intervention is needed to ensure the patient's health.

Congenital diaphragmatic hernia through the posterolateral foramen (Bochdalek) is a condition in which abdominal organs ascend into the chest cavity due to a defect in the posterolateral foramen of the diaphragm, causing compression of the lungs. The only treatment for congenital diaphragmatic hernia is surgery.