Chronic Obstructive Pulmonary Disease (COPD)


What Is It?

Chronic obstructive pulmonary disease (COPD) refers to a group of disorders in which lung function declines over time. Chronic bronchitis and emphysema, the two most common forms of COPD, are both chronic illnesses that impair airflow in the lungs. Currently, COPD affects at least millions of people in the United States, causing more than 100,000 deaths each year. In more than 80 percent of cases, the illness is related to cigarette smoking.

Chronic Bronchitis
In this respiratory disorder, the air passages in the lungs are inflamed, and the mucus-producing glands in the bronchi (the larger air passages of the lungs) are enlarged. These enlarged glands produce excessive amounts of mucus, which in turn triggers a cough. In chronic bronchitis, this cough persists for at least three months of the year for two consecutive years.

Chronic bronchitis affects about 3 percent of the people in the United States, most commonly men over age 40. Risk factors for chronic bronchitis include:

  • Tobacco smoking
  • Exposure to air pollution
  • Workplace exposure to airborne organic dusts or toxic gases, especially in cotton mills and plastic manufacturing plants
  • A history of frequent upper respiratory illnesses
  • Pneumonia during childhood
  • Sharing living space with a smoker (exposure to “secondhand smoke”)
  • Having an identical twin with chronic bronchitis

Chronic bronchitis may have different symptoms in different people. In milder cases, a cough produces only a small amount of thin, clear mucus. In other people, the mucus is thick and discolored. Symptoms similar to asthma may develop, including wheezing and shortness of breath. When significant airway obstruction develops in addition to a chronic cough, the airways become narrowed, limiting the amount of oxygen that gets to the air sacs. Blood vessels constrict in an attempt to divert the blood to better-oxygenated areas of the lung. Blood-vessel constriction leads to high pressures in the arteries that feed the lungs and puts a strain on the right side of the heart. Eventually, if blood pressure remains high enough in the lungs, heart failure develops, and blood backs up in the liver, the abdomen and legs.

In this disorder, the tiny air sacs in the lungs, called alveoli, are destroyed. The lungs are unable to contract fully, and gradually lose elasticity. Irreversible holes develop in the lung tissue, reducing the capacity for the lungs to exchange oxygen for carbon dioxide. As a result, breathing may become labored and inefficient, resulting in a persistent feeling of breathlessness.

Risk factors for emphysema include:

  • Smoking
  • Exposure to passive (“secondhand”) smoke
  • Exposure to airborne irritants or noxious chemicals (lead, mercury, coal dust, hydrogen sulfide)
  • Living in an area with significant air pollution (high levels of sulfur dioxide and particulates)

An estimated 100,000 Americans have an inherited form of emphysema in which the lungs lack a protective protein called alpha1-antitrypsin. In people with this form of the disease, lung damage can appear as early as age 30, decades sooner than the usual onset of smoking-related emphysema.


People with COPD commonly have symptoms of both chronic bronchitis and emphysema.

Chronic Bronchitis
Your first symptom may be a morning cough that brings up mucus, and that occurs at first only during the winter months. As the illness progresses, the cough begins to last throughout the day and throughout the year, with increasing amounts of mucus production. Eventually, about 15 percent of people with chronic bronchitis develop a continuous cough, breathlessness, rapid breathing or a bluish tint to the skin from lack of oxygen.

Chronic bronchitis also makes you prone to frequent respiratory infections and to potentially life-threatening flare-ups of severe breathing difficulties that often require hospitalization. If heart failure develops, there may be chest pain, together with swelling in the ankles, legs and sometimes the abdomen.

If you have emphysema, you may first feel short of breath while performing an activity such as walking or vacuuming. Because lung function decreases slowly in emphysema, you may hardly notice as breathing becomes more and more difficult. With time, you may develop increased shortness of breath, wheezing, coughing, a tight feeling in the chest, a barrel-like distended chest, constant fatigue, difficulty sleeping and weight loss.


Your doctor may suspect COPD based on your medical history, risk factors and current symptoms. During your physical examination, he or she will look for evidence of COPD by checking for rapid breathing; a bluish tint to your skin, lips or fingernails; a distended, barrel-shaped chest; use of neck muscles to breathe; abnormal breath sounds; and signs of heart failure, especially swelling in the ankle and legs.

To confirm the diagnosis, you may undergo the following tests:

  • Pulmonary function test — In this test, you will breathe into a special mouthpiece, and a machine will take measurements that will gauge the severity of airway blockage and how much your lungs inflate.

  • Blood tests — Blood tests measure the different types of blood cells or the amount of oxygen and carbon dioxide in the blood. Others are used to check for low alpha1-antitrypsin levels, especially in a nonsmoker who shows symptoms of emphysema.

  • Chest X-rays — These help to rule out pneumonia and lung cancer, and they also show heart size. If you have emphysema, chest X-rays can pinpoint areas where lung tissue has been destroyed.

  • Electrocardiogram — This test measures the electric activity of the heart and usually is done to make sure your symptoms are not caused by a heart problem.

  • Sputum analysis — A small amount of mucus is collected and tested for respiratory infection.

  • Exercise stress test — In this test, you walk on a treadmill while a specialist monitors the intensity of your exercise level. This test looks for any signs of coronary artery disease.

If you are diagnosed with the inherited form of emphysema, family members, including children, also should be tested to determine if they have a deficiency of alpha1-antitrypsin.

Expected Duration

Symptoms of chronic bronchitis tend to begin in smokers who are older than age 50. These symptoms persist and gradually worsen for the rest of the smoker’s life unless he or she quits smoking.

Most cases of emphysema are diagnosed in smokers in their 50s or 60s. People with the inherited form of emphysema can show symptoms as early as age 30. Regardless of the cause, emphysema has no cure and lasts a lifetime.


Since the majority of cases of COPD are related to smoking, you can drastically reduce your risk for this illness by avoiding cigarettes. If you smoke, get the help you need to stop. If you don’t smoke, don’t start. You also may reduce your risk of COPD by limiting your exposure to secondhand smoke and by avoiding outdoor activities when air pollution levels are high.

If you have been diagnosed with chronic bronchitis, avoid contact with anyone with symptoms of an upper-respiratory-tract infection, because even a mild cold can trigger a flare-up of bronchitis symptoms. Wash your hands frequently and avoid touching your face with your hands during the cold and flu season. Also, anyone with COPD should be vaccinated against influenza and pneumococcal pneumonia.


No treatment can fully reverse or stop the course of COPD, but steps can be taken to relieve symptoms, treat complications and minimize disability. First, your doctor will tell you to quit smoking, the most critical factor for maintaining healthy lungs. Although quitting smoking is most effective during the early stages of COPD, and can reverse some early changes, it can also slow down the rate of decline of lung function in later stages. Other COPD treatments may include:

  • Environmental changes — If your doctor believes that your COPD is caused by work-related exposure to dusts or chemicals, he or she will recommend that you change jobs. In general, people with COPD also should avoid exposure to outdoor air pollution, secondhand smoke and airborne toxins (deodorants, hair sprays, insecticides) in the home.

  • Medications — Doctors generally prescribe medications that open up the airways, called bronchodilators, taken as a spray that is inhaled or in pill form. Antibiotics also may be necessary to treat acute respiratory infections, such as bacterial pneumonia. Corticosteroids may be given to reduce airway inflammation, especially during a flare-up.

  • Exercise programs — Regular exercise builds stamina and will improve your quality of life, even if it does not directly improve lung function. Pulmonary-rehabilitation programs have been shown to lower the need for hospitalization.

  • Good nutrition — A balanced diet can help maintain stamina and improve resistance against infection. Also, getting enough water and other fluids can help to keep mucus watery and easy to drain.

  • Supplemental oxygen — If your lungs are not getting enough oxygen into your blood, oxygen therapy can improve your quality of life, increase your ability to exercise, help to relieve heart failure, prolong life, improve mental function and lift your spirits.

  • Lung-volume-reduction surgery — The most severely diseased portions of the lungs are removed, permitting the respiratory muscles and the remaining lung tissue to work more efficiently. The long-term value of this procedure is unknown.

  • Lung transplants or heart-lung transplants — Transplants are considered in selected cases of severe COPD.

When To Call A Professional

If you smoke or if you work in a job that carries a high risk of COPD, you should see your doctor once a year to be checked for early signs of lung disease. If you have family members with alpha1-antitrypsin deficiency, tell your doctor so that you can be tested for the problem, too. If you already know that you have alpha1-antitrypsin deficiency, your doctor can monitor your breathing regularly for early signs of emphysema.

Whether or not you have any risk factors for COPD, call your doctor whenever you have shortness of breath, a chronic cough with or without phlegm, or a significant decrease in your usual ability to exercise.


There is no cure for COPD, but it can be treated and controlled. By following treatment guidelines and adopting good health habits, you can enjoy many years of a fairly normal lifestyle.

In many smokers with chronic bronchitis, lung function gradually deteriorates. Patients who develop obstructive bronchitis may become more and more short of breath and eventually have to leave their jobs and remain housebound. On the other hand, if a smoker with chronic bronchitis kicks the habit, lung function can improve initially. Without tobacco exposure, lung function deteriorates more slowly, even in people with severe symptoms.

Even when emphysema is severe, patients have a good chance of surviving for five years or more if they follow treatment instructions and adopt good health habits. Research indicates that, in patients with emphysema who continue to smoke, the severity of their illness is increased dramatically, and their life span may be reduced by 10 years or more.

Johns Hopkins patient information

Last revised:

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All ArmMed Media material is provided for information only and is neither advice nor a substitute for proper medical care. Consult a qualified healthcare professional who understands your particular history for individual concerns.