For more information, visit http://www.nhlbi.nih.gov/health/health-topics/topics/copd/

What Is COPD?

COPD, or chronic obstructive pulmonary (PULL-mun-ary) disease, is a progressive disease that makes it hard to breathe. "Progressive" means the disease gets worse over time.

COPD can cause coughing that produces large amounts of mucus (a slimy substance), wheezing, shortness of breath, chest tightness, and other symptoms.

Cigarette smoking is the leading cause of COPD. Most people who have COPD smoke or used to smoke. Long-term exposure to other lung irritants—such as air pollution, chemical fumes, or dust—also may contribute to COPD.

Overview

To understand COPD, it helps to understand how the lungs work. The air that you breathe goes down your windpipe into tubes in your lungs called bronchial (BRONG-ke-al) tubes or airways.

Within the lungs, your bronchial tubes branch into thousands of smaller, thinner tubes called bronchioles (BRONG-ke-ols). These tubes end in bunches of tiny round air sacs called alveoli (al-VEE-uhl-eye).

Small blood vessels called capillaries (KAP-ih-lare-ees) run through the walls of the air sacs. When air reaches the air sacs, oxygen passes through the air sac walls into the blood in the capillaries. At the same time, carbon dioxide (a waste gas) moves from the capillaries into the air sacs. This process is called gas exchange.

The airways and air sacs are elastic (stretchy). When you breathe in, each air sac fills up with air like a small balloon. When you breathe out, the air sacs deflate and the air goes out.

In COPD, less air flows in and out of the airways because of one or more of the following:

The airways and air sacs lose their elastic quality.
The walls between many of the air sacs are destroyed.
The walls of the airways become thick and inflamed.
The airways make more mucus than usual, which can clog them.

Normal Lungs and Lungs With COPD

Figure A shows the location of the lungs and airways in the body. The inset image shows a detailed cross-section of the bronchioles and alveoli. Figure B shows lungs damaged by COPD. The inset image shows a detailed cross-section of the damaged bronchioles and alveolar walls.

In the United States, the term "COPD" includes two main conditions—emphysema (em-fih-SE-ma) and chronic bronchitis (bron-KI-tis). (Note: The Health Topics article about bronchitis discusses both acute and chronic bronchitis.)

In emphysema, the walls between many of the air sacs are damaged. As a result, the air sacs lose their shape and become floppy. This damage also can destroy the walls of the air sacs, leading to fewer and larger air sacs instead of many tiny ones. If this happens, the amount of gas exchange in the lungs is reduced.

In chronic bronchitis, the lining of the airways is constantly irritated and inflamed. This causes the lining to thicken. Lots of thick mucus forms in the airways, making it hard to breathe.

Most people who have COPD have both emphysema and chronic bronchitis. Thus, the general term "COPD" is more accurate.

Outlook

COPD is a major cause of disability, and it's the third leading cause of death in the United States. Currently, millions of people are diagnosed with COPD. Many more people may have the disease and not even know it.

COPD develops slowly. Symptoms often worsen over time and can limit your ability to do routine activities. Severe COPD may prevent you from doing even basic activities like walking, cooking, or taking care of yourself.

Most of the time, COPD is diagnosed in middle-aged or older adults. The disease isn't passed from person to person—you can't catch it from someone else.

COPD has no cure yet, and doctors don't know how to reverse the damage to the airways and lungs. However, treatments and lifestyle changes can help you feel better, stay more active, and slow the progress of the disease.

Other Names for COPD

Chronic bronchitis
Chronic obstructive airway disease
Chronic obstructive lung disease
Emphysema

What Causes COPD?

Long-term exposure to lung irritants that damage the lungs and the airways usually is the cause of COPD.

In the United States, the most common irritant that causes COPD is cigarette smoke. Pipe, cigar, and other types of tobacco smoke also can cause COPD, especially if the smoke is inhaled.

Breathing in secondhand smoke, air pollution, or chemical fumes or dust from the environment or workplace also can contribute to COPD. (Secondhand smoke is smoke in the air from other people smoking.)

Rarely, a genetic condition called alpha-1 antitrypsin deficiency may play a role in causing COPD. People who have this condition have low levels of alpha-1 antitrypsin (AAT)—a protein made in the liver.

Having a low level of the AAT protein can lead to lung damage and COPD if you're exposed to smoke or other lung irritants. If you have this condition and smoke, COPD can worsen very quickly.

Although uncommon, some people who have asthma can develop COPD. Asthma is a chronic (long-term) lung disease that inflames and narrows the airways. Treatment usually can reverse the inflammation and narrowing. However, if not, COPD can develop.

Who Is at Risk for COPD?

The main risk factor for COPD is smoking. Most people who have COPD smoke or used to smoke. People who have a family history of COPD are more likely to develop the disease if they smoke.

Long-term exposure to other lung irritants also is a risk factor for COPD. Examples of other lung irritants include secondhand smoke, air pollution, and chemical fumes and dust from the environment or workplace. (Secondhand smoke is smoke in the air from other people smoking.)

Most people who have COPD are at least 40 years old when symptoms begin. Although uncommon, people younger than 40 can have COPD. For example, this may happen if a person has alpha-1 antitrypsin deficiency, a genetic condition.

What Are the Signs and Symptoms of COPD?

At first, COPD may cause no symptoms or only mild symptoms. As the disease gets worse, symptoms usually become more severe. Common signs and symptoms of COPD include:

An ongoing cough or a cough that produces a lot of mucus (often called "smoker's cough")
Shortness of breath, especially with physical activity
Wheezing (a whistling or squeaky sound when you breathe)
Chest tightness

If you have COPD, you also may have colds or the flu (influenza) often.

Not everyone who has the symptoms above has COPD. Likewise, not everyone who has COPD has these symptoms. Some of the symptoms of COPD are similar to the symptoms of other diseases and conditions. Your doctor can find out whether you have COPD.

If your symptoms are mild, you may not notice them, or you may adjust your lifestyle to make breathing easier. For example, you may take the elevator instead of the stairs.

Over time, symptoms may become severe enough to see a doctor. For example, you may get short of breath during physical exertion.

The severity of your symptoms will depend on how much lung damage you have. If you keep smoking, the damage will occur faster than if you stop smoking.

Severe COPD can cause other symptoms, such as swelling in your ankles, feet, or legs; weight loss; and lower muscle endurance.

Some severe symptoms may require treatment in a hospital. You—with the help of family members or friends, if you're unable—should seek emergency care if:

You're having a hard time catching your breath or talking.
Your lips or fingernails turn blue or gray. (This is a sign of a low oxygen level in your blood.)
You're not mentally alert.
Your heartbeat is very fast.
The recommended treatment for symptoms that are getting worse isn't working.

How Is COPD Diagnosed?

Your doctor will diagnose COPD based on your signs and symptoms, your medical and family histories, and test results.

Your doctor may ask whether you smoke or have had contact with lung irritants, such as secondhand smoke, air pollution, chemical fumes, or dust.

If you have an ongoing cough, let your doctor know how long you've had it, how much you cough, and how much mucus comes up when you cough. Also, let your doctor know whether you have a family history of COPD.

Your doctor will examine you and use a stethoscope to listen for wheezing or other abnormal chest sounds. He or she also may recommend one or more tests to diagnose COPD.

Lung Function Tests

Lung function tests measure how much air you can breathe in and out, how fast you can breathe air out, and how well your lungs deliver oxygen to your blood.

The main test for COPD is spirometry (spi-ROM-eh-tre). Other lung function tests, such as a lung diffusion capacity test, also might be used. (For more information, go to the Health Topics Lung Function Tests article.)

Spirometry

During this painless test, a technician will ask you to take a deep breath in. Then, you'll blow as hard as you can into a tube connected to a small machine. The machine is called a spirometer.

The machine measures how much air you breathe out. It also measures how fast you can blow air out.

Spirometry

The image shows how spirometry is done. The patient takes a deep breath and then blows hard into a tube connected to a spirometer. The spirometer measures the amount of air breathed out. It also measures how fast the air is blown out.

Your doctor may have you inhale medicine that helps open your airways and then blow into the tube again. He or she can then compare your test results before and after taking the medicine.

Spirometry can detect COPD before symptoms develop. Your doctor also might use the test results to find out how severe your COPD is and to help set your treatment goals.

The test results also may help find out whether another condition, such as asthma or heart failure, is causing your symptoms.

Other Tests

Your doctor may recommend other tests, such as:

A chest x ray or chest CT scan. These tests create pictures of the structures inside your chest, such as your heart, lungs, and blood vessels. The pictures can show signs of COPD. They also may show whether another condition, such as heart failure, is causing your symptoms.
An arterial blood gas test. This blood test measures the oxygen level in your blood using a sample of blood taken from an artery. The results from this test can show how severe your COPD is and whether you need oxygen therapy.

How Is COPD Treated?

COPD has no cure yet. However, lifestyle changes and treatments can help you feel better, stay more active, and slow the progress of the disease.

The goals of COPD treatment include:

Relieving your symptoms
Slowing the progress of the disease
Improving your exercise tolerance (your ability to stay active)
Preventing and treating complications
Improving your overall health

To assist with your treatment, your family doctor may advise you to see a pulmonologist. This is a doctor who specializes in treating lung disorders.

Lifestyle Changes

Quit Smoking and Avoid Lung Irritants

Quitting smoking is the most important step you can take to treat COPD. Talk with your doctor about programs and products that can help you quit.

If you have trouble quitting smoking on your own, consider joining a support group. Many hospitals, workplaces, and community groups offer classes to help people quit smoking. Ask your family members and friends to support you in your efforts to quit.

Also, try to avoid secondhand smoke and places with dust, fumes, or other toxic substances that you may inhale.

For more information about how to quit smoking, go to the Health Topics Smoking and Your Heart article and the National Heart, Lung, and Blood Institute's "Your Guide to a Healthy Heart." Although these resources focus on heart health, they include basic information about how to quit smoking.

Other Lifestyle Changes

If you have COPD, you may have trouble eating enough because of your symptoms, such as shortness of breath and fatigue. (This issue is more common with severe disease.)

As a result, you may not get all of the calories and nutrients you need, which can worsen your symptoms and raise your risk for infections.

Talk with your doctor about following an eating plan that will meet your nutritional needs. Your doctor may suggest eating smaller, more frequent meals; resting before eating; and taking vitamins or nutritional supplements.

Also, talk with your doctor about what types of activity are safe for you. You may find it hard to be active with your symptoms. However, physical activity can strengthen the muscles that help you breathe and improve your overall wellness.

Medicines

Bronchodilators

Bronchodilators relax the muscles around your airways. This helps open your airways and makes breathing easier.

Depending on the severity of your COPD, your doctor may prescribe short-acting or long-acting bronchodilators. Short-acting bronchodilators last about 4–6 hours and should be used only when needed. Long-acting bronchodilators last about 12 hours or more and are used every day.

Most bronchodilators are taken using a device called an inhaler. This device allows the medicine to go straight to your lungs. Not all inhalers are used the same way. Ask your health care team to show you the correct way to use your inhaler.

If your COPD is mild, your doctor may only prescribe a short-acting inhaled bronchodilator. In this case, you may use the medicine only when symptoms occur.

If your COPD is moderate or severe, your doctor may prescribe regular treatment with short- and long-acting bronchodilators.

Inhaled Glucocorticosteroids (Steroids)

Doctors use inhaled steroids to treat people whose COPD symptoms flare up or worsen. These medicines help reduce airway inflammation.

Your doctor may ask you to try inhaled steroids for a trial period of 6 weeks to 3 months to see whether the medicine helps relieve your breathing problems.

Vaccines

Flu Shots

The flu (influenza) can cause serious problems for people who have COPD. Flu shots can reduce your risk of getting the flu. Talk with your doctor about getting a yearly flu shot.

Pneumococcal Vaccine

This vaccine lowers your risk for pneumococcal pneumonia (NU-mo-KOK-al nu-MO-ne-ah) and its complications. People who have COPD are at higher risk for pneumonia than people who don't have COPD. Talk with your doctor about whether you should get this vaccine.

Pulmonary Rehabilitation

Pulmonary rehabilitation (rehab) is a broad program that helps improve the well-being of people who have chronic (ongoing) breathing problems.

Rehab may include an exercise program, disease management training, and nutritional and psychological counseling. The program's goal is to help you stay active and carry out your daily activities.

Your rehab team may include doctors, nurses, physical therapists, respiratory therapists, exercise specialists, and dietitians. These health professionals will create a program that meets your needs.

Oxygen Therapy

If you have severe COPD and low levels of oxygen in your blood, oxygen therapy can help you breathe better. For this treatment, you're given oxygen through nasal prongs or a mask.

You may need extra oxygen all the time or only at certain times. For some people who have severe COPD, using extra oxygen for most of the day can help them:

Do tasks or activities, while having fewer symptoms
Protect their hearts and other organs from damage
Sleep more during the night and improve alertness during the day
Live longer

Surgery

Surgery may benefit some people who have COPD. Surgery usually is a last resort for people who have severe symptoms that have not improved from taking medicines.

Surgeries for people who have COPD that's mainly related to emphysema include bullectomy (bul-EK-toe-me) and lung volume reduction surgery (LVRS). A lung transplant might be an option for people who have very severe COPD.

Bullectomy

When the walls of the air sacs are destroyed, larger air spaces called bullae (BUL-e) form. These air spaces can become so large that they interfere with breathing. In a bullectomy, doctors remove one or more very large bullae from the lungs.

Lung Volume Reduction Surgery

In LVRS, surgeons remove damaged tissue from the lungs. This helps the lungs work better. In carefully selected patients, LVRS can improve breathing and quality of life.

Lung Transplant

During a lung transplant, your damaged lung is removed and replaced with a healthy lung from a deceased donor.

A lung transplant can improve your lung function and quality of life. However, lung transplants have many risks, such as infections. The surgery can cause death if the body rejects the transplanted lung.

If you have very severe COPD, talk with your doctor about whether a lung transplant is an option. Ask your doctor about the benefits and risks of this type of surgery.

Managing Complications

COPD symptoms usually worsen slowly over time. However, they can worsen suddenly. For instance, a cold, the flu, or a lung infection may cause your symptoms to quickly worsen. You may have a much harder time catching your breath. You also may have chest tightness, more coughing, changes in the color or amount of your sputum (spit), and a fever.

Call your doctor right away if your symptoms worsen suddenly. He or she may prescribe antibiotics to treat the infection and other medicines, such as bronchodilators and inhaled steroids, to help you breathe.

Some severe symptoms may require treatment in a hospital. For more information, go to "What Are the Signs and Symptoms of COPD?"

How Can COPD Be Prevented?

You can take steps to prevent COPD before it starts. If you already have COPD, you can take steps to prevent complications and slow the progress of the disease.

Prevent COPD Before It Starts

The best way to prevent COPD is to not start smoking or to quit smoking. Smoking is the leading cause of COPD. If you smoke, talk with your doctor about programs and products that can help you quit.

Also, try to avoid lung irritants that can contribute to COPD. Examples include secondhand smoke, air pollution, chemical fumes, and dust. (Secondhand smoke is smoke in the air from other people smoking.)

Prevent Complications and Slow the Progress of COPD

If you have COPD, the most important step you can take is to quit smoking. Quitting can help prevent complications and slow the progress of the disease. You also should avoid exposure to the lung irritants mentioned above.

Follow your treatments for COPD exactly as your doctor prescribes. They can help you breathe easier, stay more active, and avoid or manage severe symptoms.

Talk with your doctor about whether and when you should get flu (influenza) and pneumonia vaccines. These vaccines can lower your chances of getting these illnesses, which are major health risks for people who have COPD.

Living With COPD

COPD has no cure yet. However, you can take steps to manage your symptoms and slow the progress of the disease. You can:

Avoid lung irritants
Get ongoing care
Manage the disease and its symptoms
Prepare for emergencies

Avoid Lung Irritants

If you smoke, quit. Smoking is the leading cause of COPD. Talk with your doctor about programs and products that can help you quit.

Keep these irritants out of your home. If your home is painted or sprayed for insects, have it done when you can stay away for a while.

Keep your windows closed and stay at home (if possible) when there's a lot of air pollution or dust outside.

Get Ongoing Care

If you have COPD, it's important to get ongoing medical care. Take all of your medicines as your doctor prescribes. Make sure to refill your prescriptions before they run out. Bring a list of all the medicines you're taking when you have medical checkups.

Talk with your doctor about whether and when you should get flu (influenza) and pneumonia vaccines. Also, ask him or her about other diseases for which COPD may increase your risk, such as heart disease, lung cancer, and pneumonia.

Manage COPD and Its Symptoms

You can do things to help manage COPD and its symptoms. For example:

Do activities slowly.
Put items that you need often in one place that's easy to reach.
Find very simple ways to cook, clean, and do other chores. For example, you might want to use a small table or cart with wheels to move things around and a pole or tongs with long handles to reach things.
Ask for help moving things around in your house so that you won't need to climb stairs as often.
Keep your clothes loose, and wear clothes and shoes that are easy to put on and take off.

Depending on how severe your disease is, you may want to ask your family and friends for help with daily tasks.

Prepare for Emergencies

If you have COPD, know when and where to seek help for your symptoms. You should get emergency care if you have severe symptoms, such as trouble catching your breath or talking. (For more information on severe symptoms, go to "What Are the Signs and Symptoms of COPD?")

Call your doctor if you notice that your symptoms are worsening or if you have signs of an infection, such as a fever. Your doctor may change or adjust your treatments to relieve and treat symptoms.

Keep phone numbers handy for your doctor, hospital, and someone who can take you for medical care. You also should have on hand directions to the doctor's office and hospital and a list of all the medicines you're taking.

Emotional Issues and Support

Living with COPD may cause fear, anxiety, depression, and stress. Talk about how you feel with your health care team. Talking to a professional counselor also might help. If you're very depressed, your doctor may recommend medicines or other treatments that can improve your quality of life.

Joining a patient support group may help you adjust to living with COPD. You can see how other people who have the same symptoms have coped with them. Talk with your doctor about local support groups or check with an area medical center.

Support from family and friends also can help relieve stress and anxiety. Let your loved ones know how you feel and what they can do to help you.

Clinical Trials

The National Heart, Lung, and Blood Institute (NHLBI) is strongly committed to supporting research aimed at preventing and treating heart, lung, and blood diseases and conditions and sleep disorders.

NHLBI-supported research has led to many advances in medical knowledge and care. For example, this research has uncovered some of the causes of chronic lung diseases, as well as ways to prevent and treat these diseases.

Many more questions remain about chronic lung diseases, including COPD. The NHLBI continues to support research aimed at learning more about these diseases. For example, NHLBI-supported research on COPD includes studies that explore:

How certain medicines and other therapies can help treat COPD and improve quality of life for people who have the disease
Whether genetic factors increase the risk of lung damage that can lead to COPD
Whether a self-managed physical activity program is cost effective and can help people who have COPD function better
How a coping skills training program can improve quality of life for people who have COPD and their caregivers
Whether the physical properties of mucus play a role in the worsening of COPD, especially chronic bronchitis
How bacteria and toxins found in the lungs, mouth, and digestive system contribute to COPD and other lung diseases

Much of this research depends on the willingness of volunteers to take part in clinical trials. Clinical trials test new ways to prevent, diagnose, or treat various diseases and conditions.

For example, new treatments for a disease or condition (such as medicines, medical devices, surgeries, or procedures) are tested in volunteers who have the illness. Testing shows whether a treatment is safe and effective in humans before it is made available for widespread use.

By taking part in a clinical trial, you may gain access to new treatments before they're widely available. You also will have the support of a team of health care providers, who will likely monitor your health closely. Even if you don't directly benefit from the results of a clinical trial, the information gathered can help others and add to scientific knowledge.

If you volunteer for a clinical trial, the research will be explained to you in detail. You'll learn about treatments and tests you may receive, and the benefits and risks they may pose. You'll also be given a chance to ask questions about the research. This process is called informed consent.

If you agree to take part in the trial, you'll be asked to sign an informed consent form. This form is not a contract. You have the right to withdraw from a study at any time, for any reason. Also, you have the right to learn about new risks or findings that emerge during the trial.

For more information about clinical trials related to COPD, talk with your doctor. You also can visit the following Web sites to learn more about clinical research and to search for clinical trials:

Links to Other Information About COPD

NHLBI Resources

"Breathing Better With a COPD Diagnosis" (also available in Spanish)
Bronchitis (Health Topics)
"COPD: Are You at Risk?" (also available in Spanish)
COPD Learn More Breathe Better^®
How the Lungs Work (Health Topics)
Lung Function Tests (Health Topics)
Oxygen Therapy (Health Topics)
Pulmonary Rehabilitation (Health Topics)
Story of Success: COPD

Non-NHLBI Resources

Chronic Bronchitis (MedlinePlus)
COPD (MedlinePlus)
Emphysema (MedlinePlus)

Clinical Trials

Clinical Trials (Health Topics)
Current Research (ClinicalTrials.gov)
NHLBI Clinical Trials
NIH Clinical Research Trials and You (National Institutes of Health)
ResearchMatch (funded by the National Institutes of Health)

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