The question “What is COPD?” can be answered as “Chronic obstructive pulmonary disease (COPD) is a chronic inflammatory lung disease that causes obstructed airflow from the lungs.” Symptoms include difficulty breathing, coughing, mucus (sputum) production, and wheezing. It is usually caused by long-term exposure to irritating gases or particulate matter. People with COPD are at an increased risk of developing heart disease, lung cancer, and various other conditions. Although COPD is a progressive disease that worsens over time, it is treatable. With proper management, most people with COPD can achieve good symptom control and quality of life. Additionally, they can reduce the risk of associated conditions.
What is COPD?
Chronic obstructive pulmonary disease (COPD) refers to a group of long-term lung conditions that make it difficult to breathe and worsen over time. These conditions include:
- Emphysema: Emphysema is a condition caused by the destruction of the alveoli, the tiny air sacs at the ends of the smallest airways (bronchioles) in the lungs, due to exposure to irritating gases and particulate matter.
- Chronic Bronchitis: Chronic bronchitis is the inflammation of the lining of the bronchial tubes, which carry air to and from the alveoli in the lungs. It is characterized by a daily cough and mucus (sputum) production.
Most people with COPD have both emphysema and chronic bronchitis, but the severity of each type can vary from person to person.
What Are the Symptoms of COPD?
Symptoms of COPD usually do not appear until significant lung damage has occurred. The symptoms and signs of COPD may include:
- Shortness of breath, especially during physical activities
- Wheezing
- Chest tightness
- Chronic cough that produces mucus (sputum) which may be clear, white, yellow, or greenish
- Frequent respiratory infections
- Lack of energy
- Unintended weight loss (in later stages)
- Swelling in the ankles, feet, or legs
People with COPD may also experience periods called exacerbations, where their symptoms become worse than usual and persist for several days.
What Causes COPD?
In developing countries, the smoke from fuel burned for cooking and heating in poorly ventilated homes is a common cause of COPD. Your lungs rely on the natural elasticity of the bronchial tubes and air sacs to expel air from your body. COPD causes them to lose their elasticity and overexpand, leaving some air trapped in your lungs when you exhale. The causes of airway obstruction include:
- Emphysema: This lung disease destroys the fragile walls and elastic fibers of the alveoli. Small airways collapse when you exhale, impairing airflow out of your lungs.
- Chronic Bronchitis: In this condition, your bronchial tubes become inflamed and narrowed, and your lungs produce more mucus, which can further block the narrowed tubes. You develop a chronic cough trying to clear your airways.
About 1% of people with COPD have the disease due to a genetic disorder that causes low levels of a protein called alpha-1-antitrypsin (AAt). AAt is produced in the liver and secreted into the bloodstream to help protect the lungs. Alpha-1-antitrypsin deficiency can cause liver disease, lung disease, or both.
Treatment options for adults with COPD related to AAt deficiency include those used for more common types of COPD. Additionally, some people may be treated by replacing the missing AAt protein, which can help prevent further lung damage.
How is COPD Diagnosed?
To diagnose COPD, a doctor will first ask about your medical history and any exposure to chemicals, dust, or smoke. This is followed by a physical examination. Based on these, the doctor may order certain tests to diagnose COPD. These may include:
- Lung (Pulmonary) Function Tests: These tests measure how much air you can inhale and exhale and whether your lungs provide enough oxygen to your blood. The most common test, called spirometry, measures how much air your lungs can hold and how quickly you can blow air out of your lungs. You’ll blow into a large tube connected to a small machine for this. Other tests include measuring lung volumes and diffusion capacity, the six-minute walk test, and pulse oximetry.
- Chest X-Ray: A chest X-ray can show emphysema, one of the main causes of COPD. It can also help rule out other lung problems or heart failure.
- CT Scan: A CT scan of your lungs can help detect emphysema and determine whether you might benefit from COPD surgery. CT scans are also used to screen for lung cancer.
- Arterial Blood Gas Analysis: This blood test measures how well your lungs bring oxygen into your blood and remove carbon dioxide.
- Laboratory Tests: Although lab tests aren’t used to diagnose COPD, they may help determine the cause of your symptoms or rule out other conditions. For example, lab tests can be used to determine if you have the genetic disorder alpha-1-antitrypsin deficiency, which can cause COPD in some people. This test may be done if you have a family history of COPD and develop it at a young age.
How is COPD Treated?
Treatment for COPD focuses on relieving symptoms, such as cough and breathing problems, and preventing respiratory infections. The following methods are used to treat COPD:
- Supplemental Oxygen: If your blood oxygen levels are low (hypoxemia), you may need a portable oxygen tank to improve your oxygen levels.
- Vaccinations: Respiratory infections are more dangerous if you have COPD. It is especially important to get vaccinated to prevent the flu and pneumonia.
- Rehabilitation: Rehabilitation programs teach effective breathing strategies to reduce shortness of breath and improve fitness. Maintaining good form can increase what you can do with your existing lung capacity.