Chronic Obstructive Pulmonary Disease


Chronic obstructive pulmonary disease (COPD) is a disease that makes it hard to breathe and is progressive, or continues to get worse over time. COPD obstructs airflow in the lungs and the condition is not reversible. Emphysema, which is enlargement and destruction of the lungs' air sacs, and chronic bronchitis, or constant inflammation, and then scarring of the airway tubes, are included in COPD.


The lungs perform the important breathing function and help exchange oxygen for carbon dioxide in the blood. This is called gas exchange. When air enters through the nose and mouth, it travels down the trachea, or windpipe, into tubes in the lungs called airways, or bronchial tubes. Larger tubes are called bronchi, and smaller ones are called bronchioles. Small air sacs called alveoli are at the end of the bronchioles. The alveoli are springy and elastic in healthy lungs so that they can fill with air and then deflate to release it, much like a balloon. In people who have COPD, they lose their shape and take in and force out less air.

The chronic bronchitis related to COPD causes the lining of the airways to stay irritated and inflamed. The linings thicken, and lots of mucus forms. People with COPD cough often and have trouble breathing because of the mucus and narrowed airways. The changes in the alveoli from emphysema also make breathing difficult. Eventually, COPD can limit physical activity.


Most people with COPD are age 50 and older; the incidence is highest in women ages 65 to 74 and men ages 75 to 84. Because the leading cause of the disease is smoking, it often afflicts elderly people after years of tobacco use. There are a small number of people who instead have a rare form of emphysema called alpha-1 (AAT)-related emphysema. It is an inherited disorder. More than 12 million people in the United States are known to have COPD, but it could affect as many as 24 million people who have not yet been diagnosed. COPD is the third leading cause of death in the United States. More women than men die from COPD.

Causes and symptoms

Repeatedly inhaling irritants that damage the lungs and airways causes COPD in most people, and the major irritant is cigarette smoke. In fact, between 80% and 90% of COPD is caused by cigarette smoking. The number of packs smoked on average and the number of years a person smoked can affect people differently. Smoking cigars or pipes can cause COPD, but cigarettes introduce more tobacco byproducts into the lungs than smoke from cigars or pipes.

Commonly called an inhaler, the small device is filled with medications that can help expand the lungs' capacity for a short time.
A lung disease usually caused by infection that leads to inflammation. Patients often have fever, chills, cough, and difficulty breathing.
Related to or carried by the lungs
Pulmonary rehabilitation—
Intervention program for people with chronic lung diseases that involves many health disciplines and is tailored for individual patients to help improve their functioning and well-being.

COPD symptoms develop gradually, usually over years. The most common symptoms are constant coughing, production of sputum, or mucus, and shortness of breath, first with exercise and then with everyday activities. People who have COPD may feel like they cannot take deep breaths or breathe at all and experience wheezing. The symptoms worsen as time goes on, and how fast they worsen depends on the person. For example, if a patient with COPD continues smoking after diagnosis, symptoms usually worsen more quickly than if he or she stops smoking.


A smoking history is not enough to diagnose COPD. The physicians also looks for typical COPD symptoms, such as whether breathing problems have caused a change in the patient's ability to exercise or move about regularly. The physician examines the patient for physical signs of breathing trouble, such as skipped breaths, use of the muscles around the chest when breathing, pursed-lip breathing, wheezing, and chronic mild cough.

Breathing tests can help determine pulmonary function. Sprirometry is painless and relatively easy to perform but can show how well the lungs are working. The patient breathes hard into a hose that connects to a machine called a spirometer, which measures how much air the lungs can hold and how quickly the patient can blow air out of the lungs after taking a deep breath. The physician uses the measurements from this test, along with symptoms, to determine if the person is at risk for COPD, has the disease, and if so how severe the COPD is. As the disease progresses, patients also may have other tests. Chest x-rays or computed tomography scans may be taken to look for signs that suggest emphysema, and at times to ensure the symptoms are from COPD and not from another lung problem, such as cancer or pneumonia. Pneumonia is a frequent problem for people in more progressed stages of COPD. Blood tests can help measure the patient's blood gas to see if oxygen and carbon dioxide are being exchanged correctly.


People with COPD cannot be cured, but an approach that involves oxygen therapy, management of symptoms through carefully planned exercise, and quitting smoking if the person smokes, can help slow the disease's progression. This is often accomplished through the help of a pulmonary rehabilitation program, which is a comprehensive approach involving professionals from several specialties who help the patient change behaviors, manage symptoms, and learn how to improve physical conditions to manage COPD better. The program mostly involves exercise and education.

Quitting smoking

It can be difficult for people who have been lifelong smokers to kick their habit, but physicians urge all COPD patients to quit smoking as soon as they are diagnosed. To help in these efforts, physicians might prescribe special patches, gum, inhalers, or nose sprays to replace nicotine until patients can learn to live without it.


People with COPD begin exercising as part of a pulmonary rehabilitation program. How often they exercise and the type of exercise varies, depending on COPD symptoms and severity. Stretching helps keep muscles from being strained and keeps them flexible. Aerobic activity strengthens the heart and lungs and can improve breathing, but a person with COPD who has not been walking or cycling may have to work up to these types of activities. Strengthening activities might include lifting weights or repeated motions with muscles, such as those in the upper body, to improve their strength.

Changing behaviors

People with COPD often are faced with changing long-term behaviors including eating habits. For example, eating large meals makes it more difficult to breathe because the stomach pushes on the diaphragm, the muscle that helps with breathing. A well-balanced diet helps people with COPD maintain a healthy weight and fight off infections. Building self-confidence helps people with COPD stick with their exercise programs and change behaviors long-term so that they will remain active and be able to increase their levels of light physical activity. One of the values of pulmonary rehabilitation programs is that they can be tailored to help each individual patient choose the amount of exercise that is right for him or her and address behaviors or concerns that help each person the most.

Supplemental oxygen

Supplemental oxygen therapy helps people with COPD breathe more easily once they reach the severe stage of the disease. Oxygen is the only therapy that has shown reduction in deaths from COPD. Some patients begin with oxygen only when they are short of breath; others eventually may need the therapy 24 hours a day. Use of oxygen can improve sleep and mood in people with COPD and prevent heart failure in people who have severe disease. Most patients who require oxygen therapy receive in it the form of oxygen concentrators in their homes.

Other treatments

Short-term care may involve use of bronchodilators, inhaled medications that help improve the lungs' capacity for a brief time. People with COPD may frequently need antibiotics to fight infections and pneumonia. They may have other complications or illnesses in addition to COPD that have to be considered in treatment.



COPD is a serious and chronic disease that cannot be cured or reversed. With early detection and careful and regular attention to instructions from health professionals, people with COPD can learn to manage their symptoms and slow disease progression. This is particularly true if patients with COPD stop smoking. Staying healthy through proper exercise and nutrition can improve quality of life and help people live longer and reduce visits to hospitals.


The best way to prevent COPD is to avoid cigarette smoking. Even people who have genetic disorders that cause COPD are more likely to develop the disease if they smoke. People who have COPD can help avoid problems that come with COPD, such as pneumonia, by following the advice and pulmonary rehabilitation programs when it comes to exercise, nutrition, and other behaviors.



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American Lung Association, 55 W Wacker Dr., Ste. 1150, Chicago, IL, 60601, (800) 548-8252,, .

Teresa G. Odle, B.A., ELS

  This information is not a tool for self-diagnosis or a substitute for professional care.