A person can live with one lung, a medical reality made possible through the body’s remarkable ability to adapt following a procedure called a pneumonectomy. This major thoracic surgery involves the complete removal of either the right or left lung. The remaining healthy lung is generally capable of sustaining the necessary function to support life. The body compensates for the missing lung, allowing for a return to a functioning, though altered, daily life.
Reasons for Lung Removal
A pneumonectomy is reserved for severe medical conditions where less extensive surgery is not an option. Lung cancer is the most frequent reason, particularly when a tumor is large, centrally located, or involves the main airway and blood vessels, making lung-sparing resections impossible. The goal is to completely remove the diseased tissue for survival and disease control.
Other Indications
Beyond malignancy, a pneumonectomy may address catastrophic physical damage from severe trauma, such as a penetrating chest injury that has irreversibly destroyed the lung structure. Certain end-stage, non-responsive chronic infections can also demand this surgery, including advanced pulmonary tuberculosis, extensive fungal infections, or severe bronchiectasis. In all cases, the affected lung is non-functional, a source of life-threatening infection, or poses a continued risk of spreading disease. The decision to proceed is made only after testing confirms the other lung is healthy enough to manage gas exchange alone.
Physiological Compensation
The body possesses a capacity for physiological adjustment after the surgical removal of a lung. The remaining lung immediately takes on the full burden of oxygen intake and carbon dioxide removal, triggering significant anatomical and functional changes. This process allows the body to sustain life with only one lung.
Hyperinflation and Expansion
One important adaptation is hyperinflation, where the remaining lung physically expands to fill the vacant space in the thoracic cavity. This expansion occurs primarily through the distension and recruitment of existing air sacs (alveoli). While younger patients may experience some compensatory growth, adult adaptation focuses on maximizing the function of existing tissue. The remaining lung can expand to almost the size of two normal lungs combined, shifting the mediastinum toward the empty side.
Blood Flow and Mechanics
Pulmonary blood flow is completely redirected to the single remaining lung, effectively doubling the blood volume passing through its capillaries. This increased flow maximizes the efficiency of gas exchange across the alveolar membrane. Breathing mechanics also adjust, with the diaphragm and chest wall altering their movement to improve ventilatory capacity. This combination of hyperinflation, alveolar recruitment, and increased perfusion allows the remaining lung to achieve a functional capacity significantly higher than its original half-share.
Living with One Lung: Daily Life and Outlook
Living with one lung means a permanent reduction in total pulmonary capacity, despite the body adapting well. Patients often experience a noticeable reduction in exercise tolerance. Activities requiring high oxygen consumption, like running or heavy lifting, will cause shortness of breath more quickly than before surgery. However, everyday activities such as walking or light household tasks can generally be performed without difficulty.
The long-term outlook for individuals is positive, provided the underlying condition is controlled. Many patients achieve an acceptable quality of life, but this requires diligent self-care and medical follow-up. For instance, the measured forced expiratory volume in one second (FEV1) typically decreases by 34% to 44% following the procedure.
Lifelong Care
Preventing respiratory infections is a lifelong priority, as a severe infection in the single remaining lung is an immediate medical emergency. Necessary lifestyle adjustments include completely abstaining from smoking and maintaining a healthy weight to reduce the workload on the heart and lung. Regular medical check-ups, often involving pulmonary rehabilitation and monitoring of cardiopulmonary function, are important to ensure the remaining lung operates at its maximum potential.