Chronic obstructive pulmonary disease (COPD)
Chronic obstructive pulmonary disease (COPD) is a lung disease in which the lungs are damaged, making it hard to breathe. In COPD, the airways—the tubes that carry air in and out of your lungs—are partly obstructed, making it difficult to get air in and out.
Cigarette smoking is the most common cause of COPD. Most people with COPD are smokers or former smokers. Breathing in other kinds of lung irritants, like pollution, dust, or chemicals, over a long period of time may also cause or contribute to COPD.
The airways branch out like an upside-down tree, and at the end of each branch are many small, balloon-like air sacs. In healthy people, each airway is clear and open. The air sacs are small and dainty, and both the airways and air sacs are elastic and springy. When you breathe in, each air sac fills up with air like a small balloon; when you breathe out, the balloon deflates and the air goes out. In COPD, the airways and air sacs lose their shape and become floppy.
Less air gets in and less air goes out because:
- The airways and air sacs lose their elasticity (like an old rubber band).
- The walls between many of the air sacs are destroyed.
- The walls of the airways become thick and inflamed (swollen).
- Cells in the airways make more mucus (sputum) than usual, which tends to clog the airways.
COPD develops slowly, and it may be many years before you notice symptoms like feeling short of breath. Most of the time, COPD is diagnosed in middle-aged or older people.
COPD is a major cause of death and illness, and it is the fourth leading cause of death in the United States and throughout the world.
There is no cure for COPD. The damage to your airways and lungs cannot be reversed, but there are things you can do to feel better and slow the damage.
COPD is not contagious—you cannot catch it from someone else.
How the Lungs Work
The lungs provide a very large surface area (the size of a football field) for the exchange of oxygen and carbon dioxide between the body and the environment.
A slice of normal lung looks like a pink sponge filled with tiny bubbles or holes. These bubbles, surrounded by a fine network of tiny blood vessels, give the lungs a large surface to exchange oxygen (into the blood where it is carried throughout the body) and carbon dioxide (out of the blood). This process is called gas exchange. Healthy lungs do this very well.
Here is how normal breathing works
You breathe in air through your nose and mouth. The air travels down through your windpipe (trachea) then through large and small tubes in your lungs called bronchial (BRON-kee-ul) tubes. The larger tubes are bronchi (BRONK-eye), and the smaller tubes are bronchioles (BRON-kee-oles). Sometimes the word "airways" is used to refer to the various tubes or passages that air must travel through from the nose and mouth into the lungs. The airways in your lungs look something like an upside-down tree with many branches.
At the ends of the small bronchial tubes, there are groups of tiny air sacs called alveoli (al-VEE-uhl-EYE). The air sacs have very thin walls, and small blood vessels called capillaries run in the walls. Oxygen passes from the air sacs into the blood in these small blood vessels. At the same time, carbon dioxide passes from the blood into the air sacs. Carbon dioxide, a normal byproduct of the body's metabolism, must be removed.
The airways and air sacs in the lung are normally elastic—that is, they try to spring back to their original shape after being stretched or filled with air, just the way a new rubber band or balloon would. This elastic quality helps retain the normal structure of the lung and helps to move the air quickly in and out. In COPD, much of the elastic quality is gone, and the airways and air sacs no longer bounce back to their original shape. This means that the airways collapse, like a floppy hose, and the air sacs tend to stay inflated. The floppy airways obstruct the airflow out of the lungs, leading to an abnormal increase in the lungs' size. In addition, the airways may become inflamed and thickened, and mucus-producing cells produce more mucus, further contributing to the difficulty of getting air out of the lungs.
Other Names for COPD
Chronic obstructive pulmonary disease (COPD) includes
- Chronic obstructive airway disease
- Chronic obstructive lung disease
- Chronic bronchitis
In the emphysema type of COPD, the walls between many of the air sacs are destroyed, leading to a few large air sacs instead of many tiny ones. Consequently, the lung looks like a sponge with many large bubbles or holes in it, instead of a sponge with very tiny holes. The large air sacs have less surface area for the exchange of oxygen and carbon dioxide than healthy air sacs. Poor exchange of the oxygen and carbon dioxide causes shortness of breath.
In chronic bronchitis, the airways have become inflamed and thickened, and there is an increase in the number and size of mucus-producing cells. This results in excessive mucus production, which in turn contributes to cough and difficulty getting air in and out of the lungs.
Most people with COPD have both chronic bronchitis and emphysema.
Causes of COPD
Smoking Is the Most Common Cause of COPD
Most cases of chronic obstructive pulmonary disease (COPD) develop after repeatedly breathing in fumes and other things that irritate and damage the lungs and airways. Cigarette smoking is the most common irritant that causes COPD. Pipe, cigar, and other types of tobacco smoke can also cause COPD, especially if the smoke is inhaled. Breathing in other fumes and dusts over a long period of time may also cause COPD. The lungs and airways are highly sensitive to these irritants. They cause the airways to become inflamed and narrowed, and they destroy the elastic fibers that allow the lung to stretch and then return to its resting shape. This makes breathing air in and out of the lungs more difficult.
Other things that may irritate the lungs and contribute to COPD include:
- Working around certain kinds of chemicals and breathing in the fumes for many years
- Working in a dusty area over many years
- Heavy exposure to air pollution
Being around secondhand smoke (smoke in the air from other people smoking cigarettes) also plays a role in an individual developing COPD.
Genes—tiny bits of information in your body cells passed on by your parents—may play a role in developing COPD. In rare cases, COPD is caused by a gene-related disorder called alpha 1 antitrypsin deficiency. Alpha 1 antitrypsin (an-te-TRIP-sin) is a protein in your blood that inactivates destructive proteins. People with antitrypsin deficiency have low levels of alpha 1 antitrypsin; the imbalance of proteins leads to the destruction of the lungs and COPD. If people with this condition smoke, the disease progresses more rapidly.
Who Is At Risk for COPD?
Most people with chronic obstructive pulmonary disease (COPD) are smokers or were smokers in the past. People with a family history of COPD are more likely to get the disease if they smoke. The chance of developing COPD is also greater in people who have spent many years in contact with lung irritants, such as:
- Air pollution
- Chemical fumes, vapors, and dusts usually linked to certain jobs
A person who has had frequent and severe lung infections, especially during childhood, may have a greater chance of developing lung damage that can lead to COPD. Fortunately, this is much less common today with antibiotic treatments.
Most people with COPD are at least 40 years old or around middle age when symptoms start. It is unusual, but possible, for people younger than 40 years of age to have COPD.
Signs and Symptoms of COPD
The signs and symptoms of chronic obstructive pulmonary disease (COPD) include:
- Sputum (mucus) production
- Shortness of breath, especially with exercise
- Wheezing (a whistling or squeaky sound when you breathe)
- Chest tightness
A cough that doesn't go away and coughing up lots of mucus are common signs of COPD. These often occur years before the flow of air in and out of the lungs is reduced. However, not everyone with a cough and sputum production goes on to develop COPD, and not everyone with COPD has a cough.
The severity of the symptoms depends on how much of the lung has been destroyed. If you continue to smoke, the lung destruction is faster than if you stop smoking.
Doctors consider a diagnosis of chronic obstructive pulmonary disease (COPD) if you have the typical symptoms and a history of exposure to lung irritants, especially cigarette smoking. A medical history, physical exam, and breathing tests are the most important tests to determine if you have COPD.
Your doctor will examine you and listen to your lungs. Your doctor will also ask you questions about your family and medical history and what lung irritants you may have been around for long periods of time.
Your doctor will use a breathing test called spirometry (speh-ROM-eh-tree) to confirm a diagnosis of COPD. This test is easy and painless and shows how well your lungs work. You breathe hard into a large hose connected to a machine called a spirometer (speh-ROM-et-er). When you breathe out, the spirometer measures how much air your lungs can hold and how fast you can blow air out of your lungs after taking a eep breath.
Spirometry is the most sensitive and commonly used test of lung functions. It can detect COPD long before you have significant symptoms.
Based on this test, your doctor can determine if you have COPD and how severe it is. Doctors classify the severity of COPD as:
At risk (for developing COPD). Breathing test is normal. Mild signs that include a chronic cough and sputum production.
Mild COPD. Breathing test shows mild airflow limitation. Signs may include a chronic cough and sputum production. At this stage, you may not be aware that airflow in your lungs is reduced.
Moderate COPD. Breathing test shows a worsening airflow limitation. Usually the signs have increased. Shortness of breath usually develops when working hard, walking fast, or doing other brisk activities. At this stage, a person usually seeks medical attention.
Severe COPD. Breathing test shows severe airflow limitation. A person is short of breath after just a little activity. In very severe COPD, complications like respiratory failure or signs of heart failure may develop. At this stage, the quality of life is greatly impaired and the worsening symptoms may be life threatening.
Your doctor may also recommend tests to rule out other causes of your signs and symptoms. These tests include:
Bronchodilator (brong-ko-di-LA-tor) reversibility testing. This test uses the spirometer and medicines called bronchodilators. Bronchodilators work by relaxing tightened muscles around the airways and opening up airways quickly to ease breathing. Your doctor will use the results of this test to see if your lung problems are being caused by another lung condition such as asthma. However, since airways in COPD may also be constricted, your doctor can use the results of this test to help set your treatment goals.
Other pulmonary function testing. For instance, your doctor could test diffusion capacity.
Chest x ray. A chest x ray is a picture of your lungs. A chest x ray may be done to see if another disease, like heart failure, may be causing your symptoms.
Arterial blood gas. This is a blood test that shows the oxygen level in your blood. It is measured in people with severe COPD to see if oxygen treatment is recommended.
Quitting smoking is the single most important thing you can do to reduce your risk of developing chronic obstructive pulmonary disease (COPD) and slow the progress of the disease.
Your doctor will recommend treatments that help relieve your symptoms and help you breathe easier. However, COPD cannot be cured.
The goals of COPD treatment are to:
- Relieve your symptoms with no or minimal side effects of treatment
- Slow the progress of the disease
- Improve exercise tolerance (your ability to stay active)
- Prevent and treat complications and sudden onset of problems
- Improve your overall health
The treatment for COPD is different for each person. Your family doctor may recommend that you see a lung specialist called a pulmonologist (pull-mon-OL-o-gist).
Treatment is based on whether your symptoms are mild, moderate, or severe.
Medicines and pulmonary rehabilitation (rehab) are often used to help relieve your symptoms and to help you breathe more easily and stay active.
Your doctor may recommend medicines called bronchodilators that work by relaxing the muscles around your airways. This type of medicine helps to open your airways quickly and make breathing easier. Bronchodilators can be either short acting or long acting.
- Short-acting bronchodilators last about 4 to 6 hours and are used only when needed.
- Long-acting bronchodilators last about 12 hours or more and are used every day.
Most bronchodilator medicines are inhaled, so they go directly into your lungs where they are needed. There are many kinds of inhalers, and it is important to know how to use your inhaler correctly.
If you have mild COPD, your doctor may recommend that you use a short-acting bronchodilator. You then will use the inhaler only when needed.
If you have moderate or severe COPD, your doctor may recommend regular treatment with one or more inhaled bronchodilators. You may be told to use one long-acting bronchodilator. Some people may need to use a long-acting bronchodilator and a short-acting bronchodilator. This is called combination therapy.
Inhaled glucocorticosteroids (steroids)
Inhaled steroids are used for some people with moderate or severe COPD. Inhaled steroids work to reduce airway inflammation. Your doctor may recommend that you try inhaled steroids for a trial period of 6 weeks to 3 months to see if the medicine is helping with your breathing problems.
The flu (influenza) can cause serious problems in people with COPD. Flu shots can reduce the chance of getting the flu. You should get a flu shot every year.
This vaccine should be administered to those with COPD to prevent a common cause of pneumonia. Revaccination may be necessary after 5 years in those older than 65 years of age.
Pulmonary rehabilitation (rehab) is a coordinated program of exercise, disease management training, and counseling that can help you stay more active and carry out your day-to-day activities. What is included in your pulmonary rehab program will depend on what you and your doctor think you need. It may include exercise training, nutrition advice, education about your disease and how to manage it, and counseling. The different parts of the rehab program are managed by different types of health care professionals (doctors, nurses, physical therapists, respiratory therapists, exercise specialists, dietitians) who work together to develop a program just for you. Pulmonary rehab programs can include some or all of the following aspects.
Medical evaluation and management
To decide what you need in your pulmonary rehab program, a medical evaluation will be done. This may include getting information on your health history and what medicines you take, doing a physical exam, and learning about your symptoms. A spirometry measurement may also be done before and after you take a bronchodilator medicine.
You will work with your pulmonary rehab team to set goals for your program. These goals will look at the types of activities that you want to do. For example, you may want to take walks every day, do chores around the house, and visit with friends. These things will be worked on in your pulmonary rehab program.
Your program may include exercise training. This training includes showing you exercises to help your arms and legs get stronger. You may also learn breathing exercises that strengthen the muscles needed for breathing.
Many pulmonary rehab programs have an educational component that helps you learn about your disease and symptoms, commonly used treatments, different techniques used to manage symptoms, and what you should expect from the program. The education may include meeting with (1) a dietitian to learn about your diet and healthy eating; (2) an occupational therapist to learn ways that are easier on your breathing to carry out your everyday activities; or (3) a respiratory therapist to learn about breathing techniques and how to do respiratory treatments.
Program results (outcomes)
You will talk with your pulmonary rehab team at different times during your program to go over the goals that you set and see if you are meeting them. For example, if your goal is to walk every day for 30 minutes, you will talk to members of your pulmonary team and tell them how often you are walking and for how long. The team is interested in helping you reach your goals.
If you have severe COPD and low levels of oxygen in your blood, you are not getting enough oxygen on you own. Your doctor may recommend oxygen therapy to help with your shortness of breath. You may need extra oxygen all the time or some of the time. For some people with severe COPD, using extra oxygen for more than 15 hours a day can help them:
- Do tasks or activities with less shortness of breath
- Protect the heart and other organs from damage
- Sleep more during the night and improve alertness during the day
- Live longer
For some people with severe COPD, surgery may be recommended. Surgery is usually done for people who have:
- Severe symptoms
- Not had improvement from taking medicines
- A very hard time breathing most of the time
The two types of surgeries considered in the treatment of severe COPD are:
In this procedure, doctors remove one or more very large bullae from the lungs of people who have emphysema. Bullae are air spaces that are formed when the walls of the air sacs break. The air spaces can become so large that they interfere with breathing.
Lung volume reduction surgery (LVRS).
In this procedure, surgeons remove sections of damaged tissue from the lungs of patients with emphysema. A major NHLBI study of LVRS recently showed that patients whose emphysema was mostly in the upper lobes of the lung and who had this surgery, along with medical treatment and pulmonary rehabilitation, were more likely to function better after 2 years than patients who received medical therapy only. They also did not have a greater chance of dying than the other patients.
A small group of these patients who also had low exercise capacity after pulmonary rehabilitation but before surgery were also more likely to function better after LVRS than similar patients who received medical treatment only.
A lung transplant may be done for some people with very severe COPD. A transplant involves removing the lung of a person with COPD and replacing it with a healthy lung from a donor.
If you smoke, the most important thing you can do to stop more damage to your lungs is to quit smoking. For information on how to quit smoking, visit the Web site of the U.S. Office of the Surgeon General. Many hospitals have smoking cessation programs or can refer you to one.
It is also important to stay away from people who are smoking and places where you know there will be smokers.
Staying away from other lung irritants such as pollution, dust, and certain cooking or heating fumes is also important. For example, you should stay in your house when the outside air quality is poor.
Although there is no cure for chronic obstructive pulmonary disease (COPD), your symptoms can be managed, and damage to your lungs can be slowed. If you smoke, quitting is the most important thing you can do to help your lungs. Information is available on ways to help you quit smoking. You also need to try to stay away from people who are smoking or places where there is smoking.
It is important to keep the air in your home clean. Here are some things that may help you in your home:
- Keep smoke, fumes, and strong smells out of your home.
- If your home is painted or sprayed for insects, have it done when you can stay away from your home.
- Cook near an open door or window.
- If you heat with wood or kerosene, keep a door or window open.
- Keep your windows closed and stay at home when there is a lot of pollution or dust outside.
If you are taking medicines, take them as ordered and make sure you refill them so you do not run out.
See your doctor at least two times a year, even if you are feeling fine. Make sure you bring a list of medicines you are taking to your doctor visit.
Ask your doctor or nurse about getting a flu shot and pneumonia vaccination.
Keep your body strong by learning breathing exercises and walking and exercising regularly.
Eat healthy foods. Ask your family to help you buy and fix healthy foods. Eat lots of fruits and vegetables. Eat protein food like meat, fish, eggs, milk, and soy.
If your doctor has told you that you have severe COPD, there are some things that you can do to get the most out of each breath. Make your life as easy as possible at home by:
- Asking your friends and family for help.
- Doing things slowly.
- Doing things sitting down.
- Putting things you need in one place that is easy to reach.
- Finding very simple ways to cook, clean, and do other chores. Some people use a small table or cart with wheels to move things around. Using a pole or tongs with long handles can help you reach things.
- Keeping your clothes loose.
- Wearing clothes and shoes that are easy to put on and take off.
- Asking for help moving your things around in your house so that you will not need to climb stairs as often.
- Picking a place to sit that you can enjoy and visit with others.
If you are finding that it is becoming more difficult to catch your breath, your coughing has gotten worse, you are coughing up more mucus, or you have signs of infection (such as a fever and feeling poorly), you need to call your doctor right away. Your doctor may do a spirometry test, blood work, and a chest x ray. Your doctor may also:
- Order antibiotics, which are medicines that help fight off infection
- Change the type and dosage of the bronchodilator and glucocorticosteroid medicines you have been taking
- Order oxygen or increase the amount of oxygen you are currently using
It is helpful to have certain information on hand in case you need to go to the hospital or doctor right away. You should plan now to make sure you have:
- The phone numbers for the doctor, hospital, and people who can take you to the hospital or doctor
- Directions to the hospital and doctor's office
- A list of the medicines you are taking