Definition of Chronic Obstructive Pulmonary Disease (COPD)

COPD - Types, Symptoms, and Treatments

diagram of how copd affects the alveoli of the lungs
Appearance of the alveoli (small air sacs) in emphysema. A.D.A.M. Medical Encyclopedia

We are hearing that COPD is one of the leading causes of death in the United States, but what exactly does this mean, what are the symptoms, and how is it treated?

Definition: COPD - Chronic Obstructive Pulmonary Disease

COPD stands for chronic obstructive pulmonary disease, a group of lung diseases characterized by obstruction of the airways. COPD is by definition not completely reversible (in contrast to asthma) and is usually progressive over time.

Types of COPD

Diseases classified under the heading COPD include:

  • Emphysema - Emphysema is a disease which results from damage to the alveoli - the smallest airways of the lungs where the exchange of oxygen and carbon dioxide takes place, and is most often caused by smoking. Fewer alveoli are available as these are destroyed by inflammation and scarring, and those that remain become scarred, losing their elasticity and causing air trapping. You can picture this as a balloon that has lost its elasticity and air remains even when the balloon collapses (as with exhalation.)  
  • Chronic bronchitis - With chronic bronchitis the airways are chronically inflamed, resulting in scarring and thickening of the airways. This process also frequently causes an increased production of mucous. This mucous then fills the airways, further obstructing breathing.
  • Bronchiectasis - Bronchiectasis is characterized by widening and dilation of the airways, often caused by recurrent respiratory infections during childhood. Inflammation also results in the production of mucous which further obstructs the airways.

    The term COPD is used widely, as most people have a combination of both emphysema and chronic bronchitis.

    Importance and Incidence of COPD

    COPD is currently thought to be the 3rd leading cause of death in the United States. At one time COPD was considered a man’s disease, but this has changed. At the present time, there are more women than men who die from COPD each year.

    In addition to greatly impacting people's lives both physically and emotionally, COPD increases the risk of other diseases such as lung cancer and heart disease.

    Symptoms of COPD

    COPD is often asymptomatic (without symptoms) until significant damage to the lungs has already occurred. COPD is a progressive disease in which most people have periods during which they are relatively stable, alternating with intermittent exacerbations (worsening) of the disease. Common symptoms may include:

    • Shortness of breath, especially with exercise, is the most common symptom.
    • Persistent, daily cough.
    • Sputum production (coughing up phlegm) which can be clear, white, yellow, or green in color.
    • Wheezing.
    • Chest tightness
    • Cyanosis (a bluish discoloration of the lips and nail beds)
    • Weight loss (usually late in the course of the disease.)

    Causes and Risk Factors

    Some causes of COPD include:

    • Smoking is the number one cause of COPD. Roughly 25 percent of smokers will develop some degree of COPD. This includes not only cigarette smokers, but those who smoke cigars, pipes, and marijuana.  While the risk varies for different people, the combination of number of cigarettes smoked per day multiplied by years of smoking (pack-years) is closely related to risk.
    • Occupational exposures to chemicals and substances such as coal mine dust and silica.
    • Indoor air pollution, especially exposure to fumes from cooking and heating in poorly ventilated areas.
    • Outdoor air pollution.
    • Alpha-1-antitrypsin deficiency an inherited disorder.  Alpha-1-antitrypsin deficiency is responsible for 1 in 100 cases of COPD and usually occurs at a younger age than that caused by smoking. 
    • Serious lung infections in childhood.
    • The combination of asthma plus smoking.

    How is COPD Diagnosed?

    Making a diagnosis of COPD is based on a careful history, a physical exam, and a combination of tests and imaging studies. Spirometry is often considered the "gold standard" in making the diagnosis (how do I interpret my spirometry test?) Other tests may include other pulmonary function tests, arterial blood gas measurements, and a chest x-ray or chest CT scan.


    Some complications which can occur in people with COPD include:

    • Respiratory infections (often causing COPD exacerbations).
    • Heart disease, as low oxygen levels put a strain on the heart.
    • Lung cancer - COPD is an independent risk factor for lung cancer, meaning that smokers who have chronic bronchitis or emphysema are more likely to get lung cancer than non-smokers who have chronic bronchitis or emphysema.
    • Weight loss.
    • Pulmonary hypertension.
    • Depression.

    Treatments for COPD

    Guidelines for the treatment of COPD depend upon the stage and other variables. Some treatments include:

    • Quitting smoking is the single most important step in treating the disease. While it will not reverse previous damage, it can help slow the progression of the disease.
    • Flu and pneumonia shots to help prevent infections.
    • Medications - Common COPD medications include short-acting bronchodilators, long-acting bronchodilators, inhaled steroids, oral steroids, phosphodiesterase-4 inhibitors, and antibiotics.  Treatment is often broken down into 2 categories. Maintenance medications which are used daily and continuously whether or not symptoms are present. Rescue medications are drugs which are used when symptoms worsen, such as during exacerbations. 
    • Oxygen therapy - When symptoms become more severe, supplemental oxygen therapy may be needed. Thankfully there are now lightweight portable oxygen units which allow many people with COPD to live relatively active lives.
    • Pulmonary Rehabilitation – Just like rehabilitation for other ailments, pulmonary rehabilitation can make a big difference for some people living with COPD.
    • Managing Indoor Air Quality and Exposures - Avoiding secondhand smoke and other toxic fumes is an important part of managing COPD.
    • Lung Surgery – Two forms of surgery may be considered for severe COPD.  Volume reduction surgery may be used to remove damaged lung tissue. In very severe COPD, lung transplantation may be recommended.


    American College of Chest Physicians. COPD. Accessed 05/22/16.

    National Heart Lung and Blood Institute. What is COPD? Updated 07/31/13.

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