[ad_1]
COPD is a lung disease caused by inflammation from long-term exposure to irritants like cigarette smoke. It includes emphysema and chronic bronchitis, which restrict airflow and cause symptoms like shortness of breath, coughing, and fatigue. Smoking cessation is crucial for slowing disease progression and preserving lung function.
Chronic obstructive pulmonary disease (COPD) is the umbrella term used to describe emphysema and chronic bronchitis. Along with asthma and cystic fibrosis, COPD is part of a larger class of lung diseases characterized by obstruction of airflow through the respiratory system. Although the pathophysiology of COPD is not yet fully understood, COPD symptoms and progression appear to be closely related to inflammation of the lung tissue. Long-term exposure to cigarette smoke or other irritants triggers the inflammatory response of the lungs, with consequent structural and cellular modification of the tissues of the respiratory system. The pathophysiology of COPD usually manifests as emphysema, chronic bronchitis, or in many patients a combination of the two.
Cigarette smoking is generally cited as the most common risk factor for COPD. Other risk factors include workplace exposure to inhaled irritants such as coal dust or cadmium. Women, who have proportionately smaller lungs and airways than men, are more likely to develop COPD symptoms. There is also a genetic variant of the disease associated with the congenital absence of an important lung enzyme; however, this form of COPD has a clearly defined pathophysiology that is distinct from the pathophysiology of irritation-related COPD.
The common factor causing emphysema and chronic bronchitis to be grouped under the single diagnosis of COPD is airflow restriction. Since many patients exhibit symptoms of both diseases and the two share a common etiology and pathophysiology, it may make sense to refer to them as a single entity. Airflow restriction can occur due to loss of elasticity of lung tissue due to emphysema, chronic mucus congestion associated with chronic bronchitis, or persistent narrowing of the airways due to inflammation. As a result, COPD patients are often prescribed inhaler medications designed to open up the airways and make breathing easier.
Healthy lungs contain millions of tiny air sacs known as alveoli, through which oxygen is exchanged for carbon dioxide through a complex network of blood vessels. Emphysema causes these delicate sacs to rupture and destroy blood vessels, leaving existing air sacs severely damaged. When this occurs, the lungs work less efficiently. It becomes increasingly difficult to get enough oxygen or to expel carbon dioxide, and the patient may suffer from symptoms associated with oxygen deprivation.
While emphysema primarily affects the small air sacs and blood vessels of the lungs, chronic bronchitis affects the larger airways. When respiratory tissues are damaged, the body’s inflammatory response causes the airways to swell and narrow and excess mucus is secreted in an effort to protect the lungs from inhaled irritants. Unfortunately, airway inflammation and increased mucus lead to congestion and difficulty breathing. The combined pathophysiology of COPD of emphysema and chronic bronchitis leads to shortness of breath, weakness, dizziness, fatigue, and a persistent, productive cough.
In the early stages of COPD, these symptoms may not be particularly noticeable or bothersome and could easily be ignored or considered just another part of aging. As the disease progresses, COPD is characterized by frequent exacerbations in which symptoms abruptly worsen after a period of illness. These exacerbations often result in the patient being hospitalized and treated with steroids and supplemental oxygen. Over time, the pathophysiology of COPD can include a barrel chest caused by hyperinflation of the lungs, redness of the mouth and fingers due to chronic lack of oxygen, and persistent wheezing caused by narrowing and congestion of the airways.
If allowed to progress, the pathophysiology of COPD will eventually require constant oxygen supplementation and specialized nursing care. Complications of end-stage COPD include heart failure, lung collapse, and sudden respiratory failure. COPD is an irreversible disease that results in shortened overall life span and drastically reduced quality of life. The most important step in a treatment plan is to quit smoking. Smoking cessation has been shown to significantly slow disease progression and, if caught early, lung function can be maintained and quality of life preserved for years to come.
