The lungs can be divided up into basic tissue types. The airways are responsible for transmitting gases between the lungs and the environment. The alveoli are millions of tiny sacs in the lungs that exchange gases between the lungs and the blood. The interstitium includes the tissues between the alveoli and airways. This tissue is elastic, allowing the lungs to expand during inspiration and helping them to contract during expiration, like a rubber band. Some diseases damage these tissues, making the lungs inelastic, preventing them from expanding and contracting, causing breathing difficulty. These are called interstitial lung diseases.
Drugs and Inhaled Substances
Exposure to certain inhaled substances, such as at work, can lead to interstitial lung disease, according to "Harrison's Principles of Internal Medicine" by Dr. Anthony S. Fauci. When this happens, it is called occupational lung disease. Silica, beryllium and asbestos are examples of such substances. In addition, some drugs cause interstitial lung disease in certain people. Amiodarone is one such drug. It is used to treat irregular heart rhythms. Some antibiotics and chemotherapy drugs may also be responsible for interstitial lung disease.
Infections
According to "Current Medical Diagnosis and Treatment", certain infectious diseases can also cause interstitial lung disease. Tuberculosis is a type of bacteria that is transmitted by water droplets in the air. It causes lesions in the lungs and can spread to the rest of the body, causing dysfunction of infected organisms. Respiratory syncytial virus, or RSV, is a virus that can lead to interstitial lung disease.
Connective Tissue Diseases
Connective tissue disease are diseases that affect connective tissues throughout the body. These diseases can also affect the lungs, though not in every case. Lupus is a chronic disease in which the immune system attacks the organs and tissues such as the heart, lungs, joints, skin and kidneys. Rheumatoid arthritis is a disease that primarily affects the joints but can affect the organs such as the lungs.
Idiopathic Diseases
Some diseases have an unknown cause; these are called idiopathic diseases. Idiopathic pulmonary fibrosis is a disease of the connective tissue of the lungs in which, for unknown reasons, the elastic tissues are replaced by scar tissue. Sarcoidosis is a disease in which nodules of tissue grow in the lungs and other organs.
References
- "Harrison's Principles of Internal Medicine"; Anthony S. Fauci et al; 17th Ed 2008
- "Current Medical Diagnosis and Treatment "; Stephen J. McPhee and Maxine Papadakis; 49th Ed 2010
