The key physiological role of the lungs is gas exchange, swapping oxygen for carbon dioxide, to ensure the proper functioning of every cell in the body. Any disorder or disease that inhibits this process impacts an individual’s overall health by increasing the respiratory rate and decreasing the oxygen saturation of the blood. Lung diseases, or breathing disorders, can be broken down into three categories: infection, destruction, and obstruction.
Acute Breathing Disorders – Respiratory and Lung Infections
Respiratory infections are usually an acute, rather than chronic, occurrence, though other respiratory conditions and lung disorders can make a person prone to infections within the respiratory tract. Respiratory infections include:
- Influenza – viral infection of the respiratory system that can cause bronchial inflammation and increased mucus production.
- Pneumonia - bacterial infection of the lungs, most often caused by Streptococcus pneumonia, and sometimes a secondary infection of influenza.
See the World Health Organization for more details about acute respiratory infections.
Obstructive Respiratory Disorders
Obstructive disorders can be due to traumatic injury or chronic illness, which then leads to destruction of the lung tissue. The simplest obstruction that leads to hampered breathing is likely choking, when a foreign object becomes lodged in the windpipe and prevents air from moving into or out of the lungs. Physiological versions of this mechanism involve the inability of the lungs to regulate the intrapulmonary pressure, blocking air flow into the lungs.
Obstructive respiratory disorders include:
- Pulmonary edema - accumulation of fluid in the alveoli, which is often the result of congestive heart failure.
- Tension pneumothorax – traumatic injury results in the presence of air in the potential pleural space, increasing the negative pressure necessary for breathing to atmospheric pressure and resulting in a collapsed lung.
- Respiratory distress syndrome of the newborn (hyaline membrane disease) – lack of pulmonary surfactant at birth, preventing the lungs from inflating. Seen most often with premature births and is outgrown.
- Asthma – inflammatory reaction to an allergen or infection that results in bronchoconstriction and excess mucus secretion, restricting air flow to the alveoli in a way that, over time, can result in the breakdown of lung tissue.
- Bronchitis – irritation and inflammation of the airway due to infection or long-term exposure to irritants (chronic bronchitis).
Destruction of the Lung Tissue
Chronic disease often results in the destruction of the tissue affected, and the lungs are no exception.
- Spontaneous pneumothorax – presence of air in the potential pleural space in the absence of trauma, likely due to alveolar rupture during the course of chronic lung disease, resulting in a collapsed lung.
- Emphysema – degenerative disease in which the elastin in the alveoli breaks down, resulting in a loss of lung tissue elasticity, making the normally passive exhalation an active process.
- Interstitial lung disease and fibrosis – sometimes called honeycomb lung, the lung tissue scars during the course of various disease and inflammatory processes due to aberrant healing, resulting in irreversible alveolar damage and loss of elasticity.
Chronic Obstructive Pulmonary Disorder (COPD)
Consisting of the properties of all three categories, COPD is a gradual and progressive disease in which the airways become obstructed, inflamed, and damaged, leading to dysfunction and destruction via emphysema and chronic obstructive bronchitis. This chronic condition is often associated with long-term exposure to air pollutants and cigarette smoking.
Visit the National Institutes of Health for more information on chronic obstructive pulmonary disorder.
Sources:
Scanlon and Sanders. Essentials of Anatomy and Physiology, 4th edition. Saunders.
Kumar, Cotran, Robbins. Basic Pathology, 7th edition. Saunders.
Alicia Mae Prater - Alicia received her doctorate in Experimental Pathology in 2007. She has been a freelance writer and scientific editor since 2008.
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