Emphysema causes
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Emphysema causes On the Web |
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Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1]
Overview
Emphysema is a long-term, progressive disease of the lungs that primarily causes shortness of breath. In people with emphysema, the tissues necessary to support the physical shape and function of the lungs are destroyed. It is included in a group of diseases called chronic obstructive pulmonary disease or COPD (pulmonary refers to the lungs). Emphysema is called an obstructive lung disease because the destruction of lung tissue around smaller sacs, called alveoli, makes these air sacs unable to hold their functional shape upon exhalation. Emphysema is most often caused by tobacco smoking and long-term exposure to air pollution.
Causes
The majority of all emphysema cases are caused by smoking tobacco. Emphysema cases that are caused by other etiologies are referred to as secondary emphysema. [citation needed]
In rare cases, emphysema develops due to a genetic mutation that leads to alpha 1-antitrypsin deficiency. Severe cases of A1AD may also develop cirrhosis of the liver, where the accumulated A1AT leads to a fibrotic reaction that produces scarring and dysfunction; longstanding cirrosis may eventually produce liver cancer (hepatocellular carcinoma.
Some types of emphysema occur as a normal part of aging, and are particularly common found in the oldest old (85 years of age and older). At about 20 years of age, humans stop developing new alveolar tissue. In the years following the cessation of development of new alveoli, lung tissue starts to deteriorate (on a "net" basis) at a relatively slow rate. This deterioration of lung capacity and function is a normal and natural part of aging in healthy people. As alveoli die, the number of lung capillaries decrease, and the elastin of the lungs begins to break down, causing a loss of pulmonary elasticity. As people age, they also tend to lose strength and mass in their chest muscles, which weaken. bones and cartilage start to deteriorate, and posture changes. Together, all of these age-related changes in respiratory system structures can cause or contribute to the development of emphysema. Though not all elderly people will develop clinically evident emphysema, they are all at risk of decreasing respiratory function, which limits maximum performance and produces discomfort at higher levels of exertion.
Anything that causes the body to be unable to inhibit proteolytic enzymes occurring naturally in the lung can cause, or contribute to, the development of emphysema. This could include exposure to air pollution, second-hand smoke, and/or other chemicals and toxins. [citation needed]