Doctor's Notes on Chronic Obstructive Pulmonary Disease (COPD)
Chronic obstructive pulmonary disease (COPD) is a lung disease in which obstruction of the airways occurs and typically worsens over time, making it harder to breathe. Types of chronic obstructive pulmonary disease include chronic bronchitis, emphysema, and refractory (non-reversible) asthma. The most common cause of COPD is smoking. Other causes of COPD include secondhand smoke exposure, occupational exposures (for example, coal workers, welders, sensitized cotton and flour workers), untreated diseases that cause inflammation of the airways (for example, asthma), environmental exposures, and genetic conditions such as alpha-one antitrypsin deficiency.
Symptoms of chronic obstructive pulmonary disease (COPD) include productive cough or chest cold (cough is usually worse in the morning and produces a small amount of colorless sputum), shortness of breath, wheezing, and frequent colds or pneumonia. As COPD progresses and worsens, symptoms include shorter intervals between acute periods of worsening shortness of breath, discoloration of the skin (cyanosis) and right side heart failure, loss of appetite, and weight loss.
Chronic Obstructive Pulmonary Disease (COPD) Symptoms
Most people with COPD have smoked at least 10 to 20 cigarettes per day for 20 or more years before experiencing any symptoms. Thus, COPD is typically not diagnosed until the fifth decade of life (in people aged 40 to 49 years).
Common signs and symptoms of COPD are as follows:
- A productive cough or an acute chest illness is common. The cough is usually worse in the morning and produces a small amount of colorless sputum.
- Breathlessness or being short of breath (dyspnea) is the most significant symptom, but it does not usually occur until the the person's 50s or 60s.
- Wheezing is a musical, whistling, or hissing sound with breathing. Some people may wheeze, especially during exertion and when their condition worsens.
- Often people feel like they have frequent "colds" or "pneumonia." Many hospitalizations for pneumonia often turn out to be exacerbations of COPD.
The following may occur as COPD worsens:
- Intervals between acute periods of worsening of dyspnea (exacerbations) become shorter.
- Cyanosis (discoloration of the skin) and failure of the right side of the heart may occur.
- Anorexia and weight loss often develop and suggest a worse prognosis.
The Global Initiative for Chronic Obstructive Lung Disease (GOLD) Program began in 1998 with revisions in 2001, 2006, 2010, and most recently, 2014. This worldwide group has attempted to standardize the nomenclature and treatment recommendations for COPD. Their staging system is as follows; all patients have an FEV1/FVC ratio of <70%
- Stage I is FEV1 of equal or more than 80% of the predicted value.
- Stage II is FEV1 of 50% to 79% of the predicted value.
- Stage III is FEV1 of less than 30% to 49% of the predicted value.
- Stage IV is FEV1 <30% of predicted value or FEV1 <30% of predicted value plus respiratory failure, sometimes termed "end stage" COPD.
Chronic Obstructive Pulmonary Disease (COPD) Causes
Cigarette Smoking or Exposure to Tobacco Smoke
Cigarette smoking or exposure to tobacco smoke is the primary cause of COPD. Tobacco use accounts for as much as 90% of the risk for the development of this disease.
People with COPD experience a more rapid decline in what is called forced expiratory volume, or FEV. FEV is the maximum volume of air that can be exhaled within a specified time period, starting from maximal inhalation. A subscript indicates the time period in seconds. For example, FEV1 is the maximum volume of air that can be exhaled within 1 second. A decline in FEV causes a person to become short of breath and to have difficulty breathing. It is important to note, that an individual that has a more rapid decline in lung function from tobacco abuse, can return to a normal, slower decline when they quit smoking cigarettes.
It is not clear if air pollution causes COPD. However, if it does, the effect is small when compared to cigarette smoking.
The use of solid fuels for cooking and heating may cause high levels of indoor air pollution, which may then lead to the development of COPD, especially in underdeveloped countries where cooking with wood or coal is common.
Some people who develop COPD have airway hyper-responsiveness, a condition in which their airways overreact to airborne irritants, such as secondhand smoke and air pollution. The role of airway hyper-responsiveness as a risk factor for COPD in people who smoke is unclear. However, according to one hypothesis, patients who have airway hyper-reactivity and who smoke are at an increased risk of COPD and an accelerated rate of decreased lung function.
In people with chronic asthma, inflammation over time can result in permanent remodeling of the airways and result in fixed airway obstruction. It is in this way that chronic asthma becomes COPD. Generally, patients with asthma have normal lung function when they are not having an attack. It is only after years of inadequate control of airway inflammation that they can develop this fixed airway obstruction.
Alpha1-Antitrypsin (AAT) deficiency
Alpha1-antitrypsin (AAT) is a protein in the body that is produced by the liver and helps protect the lungs from damage. In AAT deficiency, the liver does not produce enough of this protein.
AAT deficiency is an inherited condition, and it is the only known genetic risk factor for COPD. It accounts for less than 1% of all cases of COPD in the United States. Severe AAT deficiency leads to emphysema at an early age; in nonsmokers, the average age of onset of emphysema is in the 50s, and in smokers, it is 40-50 years of age.
COPD is the abbreviation for chronic obstructive pulmonary disease. COPD is a lung disease that results from obstructions in the airways of the lungs that lead to breathing problems. Although COPD is a progressive disease, early diagnosis and treatment may slow its progression. COPD may be complicated by chronic bronchitis or emphysema; some patients develop both problems that lead to additional breathing problems. Some clinicians consider chronic bronchitis and emphysema as simply further manifestations of COPD.
How Does COPD Affect the Lungs?
Damage to the lung tissue over time causes physical changes in the lungs and the airways become clogged with thick mucus. Compliance (the ability of the lung tissue to expand) becomes weakened because of this lung tissue damage. This weakened compliance or elasticity of the lungs means that oxygen cannot get to the air spaces where oxygen and carbon dioxide exchange occurs in the lung. This all leads to coughing to remove the thick mucus and eventually, difficulty in breathing.
COPD (Chronic Obstructive Pulmonary Disease) QuizQuestion
COPD (chronic obstructive pulmonary disease) is the same as adult-onset asthma.See Answer
Kasper, D.L., et al., eds. Harrison's Principles of Internal Medicine, 19th Ed. United States: McGraw-Hill Education, 2015.