Emphysema
A progressive lung disease marked by enlarged alveoli and reduced gas exchange.
Emphysema is a lower respiratory tract disease marked by the permanent enlargement of the alveoli, the tiny air sacs in the lungs, due to the destruction of their walls. This breakdown replaces the normal spongy lung tissue with enlarged, air-filled spaces that can vary considerably in size, sometimes becoming very large. The resulting loss of alveolar surface area severely impairs the exchange of gases, reducing the oxygen supply available to the blood. The condition most commonly develops over many years, typically affecting middle-aged or older individuals, with tobacco smoking being the primary cause. A notable genetic risk factor is alpha-1 antitrypsin deficiency, which can lead to an earlier onset of the disease. When emphysema is accompanied by significant airflow limitation, it is classified as a major subtype of chronic obstructive pulmonary disease (COPD), a progressive condition characterized by long-term breathing difficulties. Even in the absence of COPD, the detection of emphysema on a CT scan in smokers indicates a higher risk of mortality. The disease is also a clear risk factor for lung cancer, a risk that is amplified in those who smoke. There are four anatomical types of emphysema: centrilobular (or centriacinar), panlobular (or panacinar), paraseptal (or distal acinar), and paracicatricial (or irregular). The first three types are not associated with fibrosis, while the fourth involves irregular acinar damage and is linked to scarring. Only centrilobular and panlobular emphysema are associated with significant airflow obstruction, with centrilobular emphysema being about twenty times more common and the only type directly linked to smoking. Osteoporosis is a frequent comorbidity, and the repeated use of systemic corticosteroids to treat exacerbations is a significant risk factor for bone loss.
Quick Facts
- Field
- Pulmonology
- Symptoms
- Shortness of breath, chronic cough
- Onset
- Over 40 years old
- Duration
- Long term
- Causes
- Tobacco smoking
- air pollution
- genetics
Facts from the source article.
Lore & Background
Emphysema is characterized by the permanent and abnormal enlargement of the air spaces within the lungs, known as the alveoli, which occurs due to the breakdown of the alveolar walls. This destruction replaces the normal spongy tissue of the lung with enlarged, air-filled spaces that can vary considerably in size, sometimes becoming very large. The loss of alveolar walls reduces the total surface area available for gas exchange, thereby diminishing the oxygen supply to the blood. The condition is a lower respiratory tract disease and typically affects middle-aged or older individuals, as it develops slowly over time, most often due to tobacco smoking. A genetic risk factor, alpha-1 antitrypsin deficiency, can lead to an earlier presentation. Emphysema is a major subtype of chronic obstructive pulmonary disease (COPD) when significant airflow limitation is present, and its presence on a CT scan, even without COPD, indicates a higher mortality risk in smokers. There are four main anatomical types: centrilobular (associated with smoking and the most common), panlobular (linked to alpha-1 antitrypsin deficiency), paraseptal, and paracicatricial (which involves irregular acinar damage and fibrosis). Only centrilobular and panlobular types are associated with significant airflow obstruction. A physical sign of emphysema is the development of a barrel chest. Osteoporosis is a frequent comorbidity, and the repeated use of systemic corticosteroids for exacerbations is a significant risk factor for this bone condition.
Reader's Guide
Emphysema is a significant lower respiratory tract disease and a major subtype of chronic obstructive pulmonary disease (COPD). Its hallmark is the permanent enlargement of alveoli due to the destruction of alveolar walls, which impairs gas exchange and leads to shortness of breath. The condition is most commonly caused by tobacco smoking, but genetic factors like alpha-1 antitrypsin deficiency can also cause it, often presenting earlier. There are four anatomical types: centrilobular (most common, associated with smoking), panlobular (linked to alpha-1 antitrypsin deficiency), paraseptal, and paracicatricial (associated with fibrosis). Only centrilobular and panlobular types cause significant airflow obstruction. Emphysema is a clear risk factor for lung cancer, and its presence in smokers confers higher mortality even without COPD. Osteoporosis is a common comorbidity, exacerbated by systemic corticosteroid use. Diagnosis often relies on imaging, but the condition is frequently underdiagnosed due to overlapping symptoms with other lung diseases.
Did You Know?
- Centrilobular emphysema is about 20 times more common than panlobular emphysema.
- The intravenous use of methylphenidate (Ritalin) can lead to emphysematous changes known as Ritalin lung.
Frequently Asked Questions
What is Emphysema known for?
Its signature ability is the irreversible destruction of alveolar walls, which collapses the lung's gas-exchange surface and leaves patients increasingly breathless with even minimal exertion. Tobacco smoking is its most common trigger, though a genetic shortfall in alpha-1 antitrypsin can also set it off.
What are Emphysema's known variants?
Four recognized subtypes exist—centrilobular, panlobular, paraseptal, and paracicatricial—differing in exactly which regions of the acinus are destroyed. Centrilobular is the most frequently seen and is most tightly linked to long-term smoking, while panlobular is the variant most associated with alpha-1 antitrypsin deficiency.
More in Common Diseases & Disorders
Spotted an error? Know more?
Reader corrections go straight into our review queue. Suggest an edit · How this site is sourced