The lungs, an organ of the respiratory system, function to intake air, exchange gases and exhale waste produced by cells. As the lungs expand, air enters the mouth and nose, travels through the trachea, enters the bronchi that branch into a series of smaller tubes known as bronchioles. The bronchioles connect to tiny elastic air sacs—alveoli—that function to exchange oxygen and carbon dioxide with the blood in the surrounding capillaries. Degenerative lung diseases cause damage to the lungs that progressively worsens over time and interferes with their ability to function.
Pulmonary Fibrosis
Pulmonary fibrosis, classified as one of over 100 interstitial lung diseases, occurs when scar tissue develops in the lungs, according to the Pulmonary Fibrosis Foundation. The cause of pulmonary fibrosis often remains undetected, leading to a diagnosis of idiopathic pulmonary fibrosis. As scar tissue builds up in the lung, the lung tissue thickens and the lungs lose their ability to transfer oxygen into the blood.
In the early stages of the disease, patients fail to notice any symptoms. As the disease progresses, shortness of breath, medically known as dyspnea, becomes apparent. Other symptoms of pulmonary fibrosis include a chronic cough, fatigue, weakness and chest discomfort. Severe shortness of breath can interfere with eating leading to a loss of appetite and weight loss.
Chronic Obstructive Pulmonary Disease
Chronic obstructive pulmonary disease, also called COPD, describes a degenerative lung disease that causes a persistent obstruction of the airways. COPD affects approximately 12 million people in the United States and remains the fourth leading cause of death, according to the Merck Manual. Airway obstruction occurs due to chronic bronchitis, emphysema or both.
The obstructed airways trap air in the lungs even after a complete exhalation. This means that less air flows in during inhalation. The end result includes an increased effort to breath, low oxygen levels and a high carbon dioxide levels in the blood. In the early stages of COPD, symptoms include a mild cough and shortness of breath during exertion. As the disease progresses the shortness of breath worsens, patients lose weight and the cough can produce blood.
Emphysema
Emphysema, a condition that can lead to COPD, causes damage to the alveolar walls—the walls of the tiny air sacs. As the walls become damaged the air sacs lose their elasticity and fail to fill with air. The damaged walls also allow air sacs to combine, creating fewer but larger sacs. The two lungs contain over 600 million alveoli, according to the Franklin Institute, which provides maximum space for oxygen exchange with the blood to occur.
Destruction of the air sacs or the formation of larger sacs leads to a decrease in the amount of air coming into contact with the capillaries therefore decreasing the amount of oxygen reaching the bloodstream. Symptoms include shortness of breath, wheezing, chest tightness, chronic cough, loss of appetite and weight loss.
