Chronic obstructive pulmonary disease (COPD) refers to a group of disorders that damage the lungs and make breathing increasingly difficult over time. The two most common forms of COPD are chronic bronchitis and emphysema. Both are chronic (long-term) illnesses that impair airflow in the lungs. Currently, COPD affects millions of people in the United States, causing more than 100,000 deaths each year. In more than 80% of cases, the illness is related to cigarette smoking.
In this respiratory disorder, the air passages in the lungs are inflamed, and the mucus-producing glands in the larger air passages of the lungs (bronchi) are enlarged. These enlarged glands produce too much mucus, which triggers a cough. In chronic bronchitis, this cough lasts for at least three months of the year for two consecutive years.
Chronic bronchitis affects about 3% of the people in the United States, most commonly men older than 40. You are more likely to develop chronic bronchitis is you:
• Smoke tobacco
• Are exposed to air pollution
• Are exposed in the workplace to airborne organic dust or toxic gases, especially in cotton mills and plastic manufacturing plants
• Have a history of frequent respiratory illnesses
• Live with a smoker
• Have 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. Eventually, 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. This increases blood pressure in the arteries that feed the lungs, and strains 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, 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. Holes develop in the lung tissue, reducing the lungs’ ability to exchange oxygen for carbon dioxide. As a result, breathing may become labored and inefficient, and you may feel breathless most of the time.
You are more likely to develop emphysema if you:
• Are exposed to passive (“secondhand”) smoke
• Are exposed to airborne irritants or noxious chemicals (lead, mercury, coal dust, hydrogen sulfide)
• Live in an area with significant air pollution (high levels of sulfur dioxide and particulates)
An estimated 100,000 people in the United States have an inherited form of emphysema in which the lungs lack a protective protein called alpha-1-antitrypsin. In people with this form of the disease, lung damage can appear as early as age 30, decades sooner than smoking-related emphysema usually starts.
People with COPD commonly have symptoms of both chronic bronchitis and emphysema.
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, and produces more mucus. Eventually, about 15% 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 during activities 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 will examine you, looking 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, he or she may order the following tests:
• Pulmonary function test — In this test, you will breathe into a special mouthpiece, and a machine will take measurements to test how much your airways are blocked 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 alpha-1-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. This test looks for any signs of coronary artery disease.
No treatment can fully reverse or stop 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 ask your employer to find an alternative work environment. 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. Daily inhaled corticosteroids may be given to reduce airway inflammation. For flare-ups, an oral corticosteroid called prednisone often is prescribed.
• 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 — In carefully selected patients, surgery to remove the most severely diseased portions of the lungs allows the less damaged areas of the lungs to expand better. The long-term value of this procedure is unknown.
• Lung transplants or heart-lung transplants — Transplants are rarely an option, except in very selected cases of early onset, severe COPD.