Sanja Jelic, MD, is board-certified in sleep medicine, critical care medicine, pulmonary disease, and internal medicine.
COPD is a progressive, irreversible inflammatory disease of the lungs that makes it difficult to breathe. COPD affects more than nine million Americans and predominantly occurs in people who are middle-aged or older. It's also the fourth-leading cause of death in the United States.
Cigarette smoking is the most common cause of COPD. Common symptoms include a persistent cough, wheezing, production of phlegm, shortness of breath, and a feeling of tightness in your chest, though these symptoms may not be noticeable until you’re in the later stages of the disease.
While COPD is not curable, it is a preventable and treatable illness. The earlier you start treatment, the better your prognosis.
COPD is often asymptomatic until significant damage to the lungs has occurred. When symptoms do start to appear, shortness of breath is often the first one. Patients may feel like they are hungry for air or working hard to breathe. Other possible symptoms of COPD include fatigue, wheezing, a chronic cough, mucous (phlegm) production, and chest tightness.
Cigarette smoking, whether in the past or present, is the most common cause of COPD. Exposure to secondhand smoke, air pollution, chemical fumes (often in the workplace), or dust may also cause COPD. Rarely, a genetic disorder called alpha-1-antitrypsin (AAT) deficiency is the culprit.
If a patient has symptoms suggestive of COPD (e.g., persistent or worsening shortness of breath), the diagnosis can be confirmed with a pulmonary function test called spirometry. Laboratory and imaging tests may also be ordered to rule out alternative diagnoses like heart failure or pulmonary fibrosis.
COPD stands for chronic obstructive pulmonary disease. It is a general term that includes various progressive lung diseases, most commonly chronic bronchitis (irritation of the bronchial tubes) and emphysema (destruction of the air sacs).
The GOLD system, which stands for Global Initiative for Chronic Obstructive Lung Disease, classifies COPD into the following four stages:
GOLD 1: Mild
GOLD 2: Moderate
GOLD 3: Severe
GOLD 4: Very Severe
These stages are based on forced expiratory volume (FEV1) readings, which is the amount of air a person can forcefully breathe out in one second.
COPD is associated with a reduced lifespan. While there is no way to determine a person's exact life expectancy, it can be predicted using a tool called the BODE index. This index utilizes four measures: body mass index (BMI), airway obstruction, dyspnea (shortness of breath), and exercise tolerance.
This is a rare genetic condition caused by the lack of a protein called Alpha-1 antitrypsin (AAT). This protein normally protects the lungs from damage. A deficiency results in breathing difficulties from emphysema. Diagnosis of AAT deficiency is made through a simple blood test.
An arterial blood gas (ABG) test measures the levels of oxygen and carbon dioxide in blood from an artery (not a vein). It also measures the blood’s acidity or pH level. Results of the test can help your doctor see how well your lungs are functioning.
Chronic bronchitis is a progressive lung disease that comprises COPD (along with emphysema). Chronic bronchitis develops when the tubes that carry air in and out of your lungs become inflamed. This inflammation develops slowly over time, and causes patients to experience long-term breathing problems and a cough that brings up phlegm.
Emphysema, along with chronic bronchitis, is one of the main lung diseases that comprises COPD. Emphysema occurs when the tiny air sacs (called alveoli) located deep within the lungs become damaged. Breathing difficulties develop because air is trapped inside the lungs, and there is less oxygen available to move into the bloodstream.
Lung disease is a general term that describes any health condition that affects the lungs, such as COPD, asthma, pneumonia, and lung cancer. The lung’s main function is to move oxygen into the bloodstream from the air you breathe in. Your lungs also remove the waste gas carbon dioxide as you breathe out.
These noninvasive tests evaluate how well your lungs are working. Spirometry, which is used to diagnose COPD, is a type of pulmonary (lung) function test that entails taking a deep breath in and blowing out as fast and as hard as you can into a tube that is hooked up to a machine.
Centers for Disease Control and Prevention. Chronic obstructive pulmonary disease. Updated February 21, 2020.
Miravitlles M, Ribera A. Understanding the impact of symptoms on the burden of COPD. Respir Res. 2017;18(1):67. doi:10.1186/s12931-017-0548-3
American Lung Association. How lungs work: the respiratory system. Updated April 2020.
American Lung Association. Chronic obstructive pulmonary disease (COPD).