Chronic obstructive pulmonary disease (COPD) is a progressive lung disease that makes breathing difficult. It is a relatively common condition.
According to the Centers for Disease Control and Prevention (CDC), around 16 million people in the United States have COPD.
Doctors use a grading system to determine the severity of the disease and monitor its progression over time.
Below, we describe this system and explore COPD symptoms and treatments, as well as strategies for prevention and management.
Emphysema causes the air sacs, or alveoli, of the lungs to become damaged and lose their elasticity. This makes it difficult for the alveoli to exchange gases.
Chronic bronchitis refers to persistent inflammation of the bronchiole tubes that carry air into and out of the lungs. This inflammation causes the bronchioles to thicken and produce excessive amounts of mucus.
Both emphysema and chronic bronchitis limit the amount of air that flows into and out of the lungs, causing breathing difficulties.
When diagnosing COPD, a doctor assesses symptoms and administers a spirometry test to evaluate how well the lungs are working.
This involves using a device called a spirometer to measure the force with which the person can exhale.
A doctor may consider a diagnosis of COPD if a person reports:
- a persistent cough
- an excessive production of mucus, or sputum
- tightness in the chest
- shortness of breath
Evaluating lung function
The doctor determines how well the lungs are working by taking into account the following measurements:
Forced expiratory volume
This measurement, known as FEV1, represents the amount of air that a person can force out of their lungs in 1 second.
The doctor compares the person’s actual FEV1 value to their expected FEV1 value, which is based on age, race, gender, and height.
If the person’s FEV1 is lower than expected, it indicates reduced lung function. The greater the difference between the actual and expected FEV1 values, the greater the severity of the disease.
Forced vital capacity
This measurement, written as FVC, refers to the amount of air that a person can expel from their lungs after breathing in as deeply as they can.
The doctor will use FEV1 and FVC values to calculate a ratio. In order to meet the criteria for COPD, a person’s FEV1 to FVC ratio must be less than 70%.
The recently revised staging system for COPD takes into account two factors: airflow limitation and symptom history.
It uses a number based on the FEV1 measurement to demonstrate the severity of airflow limitation:
|Mild, or GOLD 1||≥80|
|Moderate, or GOLD 2||50–70|
|Severe, or GOLD 3||30–49|
|Very severe, or GOLD 4||<30|
The staging system also assigns a letter that reflects the person’s symptom burden and the history of moderate to severe exacerbations.
A healthcare professional assesses symptom burden using either the Modified Medical Research Council (mMRC) questionnaire or the COPD assessment test (CAT):
|Moderate or severe exacerbation history|
|≥ 2 or ≥ 1 leading to hospital admission||C||D|
|0 or 1 (not leading to hospital admission)||A||B|
CAT < 10
|mMrc ≥ 2|
CAT ≥ 10
For example, if someone with a FEV1 of at least 80 has a CAT score of at least 10, and they have experienced one or more moderate exacerbations, a healthcare professional would measure their stage as GOLD 1 group D.
As COPD progresses, a person’s symptoms may become more severe. In the more advanced stages of COPD, a person may experience:
People with more advanced COPD may also begin to experience complications, such as:
- bacterial infections
- pulmonary hypertension
- acute or chronic respiratory failure
The right treatments for COPD depend largely on the degree of symptoms and the frequency with which they worsen.
The options are varied, but they typically include:
- Bronchodilators: These medications assist breathing by relaxing the muscles around the airways.
- Inhaled corticosteroids: These drugs assist breathing by reducing airway inflammation.
- Oxygen therapy: This involves breathing oxygen through a machine.
- Pulmonary rehabilitation: This involves education and exercises to help improve lung function, improve the quality of life, and reduce the severity of symptoms.
Also, surgery is sometimes necessary when airflow limitation and symptoms are severe. The procedure might involve:
- Bullectomy: This is surgery to remove an air pocket or pockets from the lungs to help ease breathing difficulties.
- Lung volume reduction: This involves removing the least functional part of the lung to improve function in the remaining healthy lung tissue. It is only suitable for 1–2% of people with COPD.
- Lung transplantation: This involves replacing a diseased lung with a healthy lung from a donor.
COPD is typically caused by long-term exposure to pollutants, irritants, allergens, or a combination.
In the U.S., the most common cause of COPD is exposure to cigarette smoke. As such, a person can lower their risk of developing COPD by quitting smoking and avoiding exposure to secondhand smoke.
People who have COPD may find that avoiding pollutants, including smoke, irritants, and allergens can help delay the progression of the disease.
Other strategies for managing COPD include:
- Vaccinations: People with COPD have an increased risk of complications of flu and pneumonia. It is crucial to have up-to-date vaccinations for these diseases.
- Physical activity: Regular physical activity can help a person manage their COPD symptoms.
- Dietary changes: Improving the diet may help delay the progression of COPD and reduce the risk of complications, such as weight loss and fatigue.
COPD is a serious condition that can be life threatening in its more severe stages.
Anyone with any COPD symptoms should see a doctor as soon as possible, as early treatment may help delay the progression of the disease.
A 2020 review notes that COPD causes symptoms that are similar to those of other serious conditions, such as:
Often, simple tests and exams can help determine the cause of the symptoms.
COPD is a relatively common progressive respiratory disease. When diagnosing COPD, a doctor will determine the stage of the disease, in order to recommend the best course of treatment.
Various strategies and activities can help delay the progression of COPD, including avoiding or limiting exposure to pollutants, irritants, and allergens. Surgery may be necessary to treat more severe cases.
Overall, early intervention is key, and anyone with COPD symptoms should see a healthcare provider as soon as possible.