Chronic obstructive pulmonary disease (COPD) is the fourth leading cause of death in the United States. Commonly caused by the inhalation of noxious particles or gas, such as tobacco smoke, COPD is an abnormal inflammation of the lung. It is often misdiagnosed as asthma, resulting in inadequate treatment. COPD can also be confused with pneumonia, influenza, or bronchitis.
Causes of COPD
Approximately 80% to 90% of all COPD cases in the United States are the result of tobacco smoking habits. Patients of the age 65 and over are also at a higher risk for COPD. The best method of preventing COPD is to avoid external risk factors, such as smoke and other forms of air pollution. If working in an environment with high risk of air pollution, caution should be exercised by the employer to prevent the development of COPD in healthy individuals.
Certain behaviors or risk factors for developing COPD, such as:
- Autoimmune diseases
- Exposure to noxious particles through work, such as coal or gold mining
- Urban air pollution
- Repeated lung infections
- Excessive consumption of sodium nitrite, commonly found in cured meats
Types of COPD
COPD is commonly classified into two main categories. While both forms of COPD are still inflammatory conditions within the lungs, the specific parts of the lungs that are most affected can differ. This results in variances between symptoms, prognosis, and treatment for each patient. The two main types of COPD are chronic bronchitis and emphysema.
This form of COPD occurs when the lung damage and inflammation are concentrated within the large airways. Goblet cells lining the major paths for air inhalation multiply, increasing both the number and size of these cells. As a result, the mucous glands also multiply. This generates more mucus than is necessary, further contributing to the constriction of the major airways and causing the patient to cough up excess mucus. The inflammation causes scarring and remodeling of the airways, condensing the walls and further narrowing the paths for air. It is difficult for the patient to get enough oxygen.
Inflammation and damage of the air sacs, or alveoli, is known as emphysema. The air spaces farthest from the major airways enlarge. This causes deterioration of the terminal bronchioles and the air spaces walls. The weakening of the air space walls indicates a smaller surface area available for the exchange of carbon dioxide and oxygen during breathing. The damage caused to the air sacs also results in poor lung elasticity. This increases the chances of lung airway collapse, constricting the patient’s airflow.
Certain symptoms should prompt further lung investigation by a medical specialist. These involve:
- History of cigarette smoking
- Headaches, usually due to lack of oxygen
- Dyspnea, or a shortness of breath
- Rhonchi, or a decreased intensity of breathing sounds
- Chronic cough, often in addition to sputum production
- Drowsiness or fatigue
- Tachypnea, or a rapid breathing rate
- Exhalation taking longer than inhalation
- Hyperaeration, or enlargement of the chest in a front-to-back measurement
- Breathing through pursed lips
- Using muscles in the neck to ease the breathing process
- Wheezing or crackling noises in the lungs when examining patient with a stethoscope
COPD can frequently be misdiagnosed as:
- Pulmonary edema
If a patient is reporting breathlessness, consistent coughing and mucus production, or a history of smoking cigarettes, the medical professional should run tests for COPD. Lung function tests are key elements in diagnosing COPD. The primary lung function test used in diagnosing COPD is called spirometry. This allows the doctor to measure the volume of air that can be exhaled within the first second of the patient’s breath.
Spirometry also allows the physician to analyze the amount of air the patient can exhale in one entire breath. At least 70% of the lung’s air capacity is typically expelled within the first second when the patient breathes out. Any ratio less than 70% indicates that the patient is experiencing COPD. When combined with an analysis of breathlessness and exercise limits, the medical practitioner should be able to establish the severity of the patient’s COPD.
Other tests that may help diagnose a patient’s lung conditions include:
- Chest x-rays
- Pulmonary function tests, complete with measurements of gas transfer and lung volume
- CT scans of the chest
- Blood samples