A diseased or failing lung is replaced by a healthy lung of the matched donor by a surgical procedure. The lung transplant can be done either for single or double lungs.

when an individual has a damaged or diseased lung, it will become difficult for the body to receive the oxygen required for survival. Thus vital functions like a gas exchange, removal of carbon dioxide from the body, metabolism and other functions will get affected. Pulmonary diseases like scarring of the lungs (pulmonary fibrosis), chronic obstructive pulmonary disease (COPD), including emphysema, cystic fibrosis and high blood pressure in the lungs (pulmonary hypertension) are among the common causes of lungs failure.

When any organ stops functioning properly and fails because of pulmonary disease; doctors prefer organ transplant to add years to a patient's life span and improve health conditions.