The normal function of lung cells is to absorb oxygen from the air and expel carbon dioxide from the blood, a process called respiration. When lung cancer develops, abnormal tumor cells grow out of control and begin to interfere with this vital process. Left untreated, lung cancer will eventually cause breathing complications leading to respiratory failure, ultimately resulting in death.
Obstructed Airway
As a tumor grows within the air passages of the lungs, it may grow large enough to become a physical obstruction that blocks airways. Airway blockage may lead to a persistent cough, moderate-to-severe chest pain, and shortness of breath. In addition to shortness of breath and heavy, labored breathing, there is sometimes a noticeable wheezing associated with an obstructed airway.
Pneumonia
Those suffering from lung cancer face a higher risk of developing lung infections like pneumonia. Pneumonia can be caused by a number of different factors, including infectious pathogens like bacteria, virus and fungi. However, pneumonia is the general description of an inflammation of the lungs that causes the air sacs of the lungs to fill with fluid. This reduces the amount of oxygen absorbed from the air, ultimately resulting in a lower blood oxygen level.
Collapsed Lung
Obstructions caused by cancerous growth within the airways of the lungs may also lead to a partial or complete collapse of the lungs, also called atelectasis. The air sacs within the lung become deflated because of the added stress that is placed upon the lungs usually due to labored breathing. According to MayoClinic.com, a collapsed lung can be caused by an obstructive tumor, or be a direct complication of pneumonia should a person be suffering from both.
Pulmonary Fibrosis
Lung cancer may lead to other lung diseases like interstitial pulmonary fibrosis. Pulmonary fibrosis describes the excessive inflammation and healing process of lung tissue that eventually forms hardened, fibrous scar tissue. Pulmonary fibrosis may be a direct result of lung cancer or its complications like pneumonia. Those that experience hardening of the lungs through pulmonary fibrosis typically have a poor outlook, with survival of usually less than 3 years after the condition has been identified.
