Chronic Obstructive Pulmonary Disease

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 the lungs are partly obstructed, making it difficult to get air in and out.

Overview

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 called alveoli 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. While breathing in, each air sac fills up with air like a small balloon; while breathing 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.

The illustration show the respiratory system and cross-sections of healthy alveoli and alveoli with COPD. Source: NHLBI, NIH

The illustration show the respiratory system and cross-sections of healthy alveoli and alveoli with COPD.

COPD develops slowly, and it may be many years before any symptoms are noticed. One common early symptom is 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 that can be done to feel better and slow the damage.

COPD is not contagious. A person cannot catch it from someone else.

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:

• Air is breathed in through the nose and mouth. The air travels down through the windpipe (trachea) then through large and small tubes in the lungs called bronchial tubes. The larger tubes are bronchi, and the smaller tubes are bronchioles. 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 the 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. 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

• Chronic obstructive airway disease
• Chronic obstructive lung disease

In the United States, chronic obstructive pulmonary disease (COPD) includes:

• Emphysema
• 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

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—are tiny bits of information in the body cells passed on by the 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 is a protein in the 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.

Chances of Developing Chronic Obstructive Pulmonary Disease

Risk factors

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

The signs and symptoms of chronic obstructive pulmonary disease (COPD) include:

• Cough
• Sputum (mucus) production
• Shortness of breath, especially with exercise
• Wheezing (a whistling or squeaky sound that occurs during breathing)
• 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. With continued smoking, the lung destruction is faster than in someone who has quit smoking.

Diagnosis

Exams and Tests

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 COPD exists.

The doctor will do an examination and listen to the lungs. He or she will also ask questions about family and medical history and what lung irritants may have been around for long periods of time.

Breathing Tests

The doctor will use a breathing test called spirometry to confirm a diagnosis of COPD. This test is easy and painless and shows how well the lungs work. The patient will breathe hard into a large hose connected to a machine called a spirometer. When breathing out, the spirometer measures how much air the lungs can hold and how fast it can be blown out after taking a deep breath.

Spirometry is the most sensitive and commonly used test of lung functions. It can detect COPD long before there are significant symptoms.

Based on this test, the doctor can determine if COPD is present 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, a person may not be aware that airflow in the 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.

The doctor may also recommend tests to rule out other causes of the signs and symptoms. These tests include:

• Bronchodilator 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. The doctor will use the results of this test to see if the lung problems are being caused by another lung condition such as asthma. However, since airways in COPD may also be constricted, he or she can use the results of this test to help set treatment goals.
• Other pulmonary function testing. For instance, the doctor could test diffusion capacity.
• Chest x ray. A chest x ray is a picture of the lungs. A chest x ray may be done to see if another disease, like heart failure, may be causing the symptoms.
• Arterial blood gas. This is a blood test that shows the oxygen level in the blood. It is measured in people with severe COPD to see if oxygen treatment is recommended.

Treatment

Quitting smoking is the single most important thing that one can do to reduce the risk of developing chronic obstructive pulmonary disease (COPD) and slow the progress of the disease.

The doctor will recommend treatments that help relieve symptoms and help make breathing easier. However, COPD cannot be cured.

The goals of COPD treatment are to:

• Relieve symptoms with no or minimal side effects of treatment
• Slow the progress of the disease
• Improve exercise tolerance (the ability to stay active)
• Prevent and treat complications and sudden onset of problems
• Improve overall health

The treatment for COPD is different for each person. A family doctor may recommend that seeing a lung specialist called a pulmonologist.

Treatment is based on whether the symptoms are mild, moderate, or severe.

Medicines and pulmonary rehabilitation (rehab) are often used to help relieve symptoms and to help make breathing easier and staying active.

Medications

Bronchodilators

The doctor may recommend medicines called bronchodilators that work by relaxing the muscles around the airways. This type of medicine helps to open the 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 the lungs where they are needed. There are many kinds of inhalers, and it is important to know how to use the inhaler correctly.

In cases of mild COPD, the doctor may recommend that using a short-acting bronchodilator. Then it will be necessary to use the inhaler only when needed.

In cases of moderate or severe COPD, the doctor may recommend regular treatment with one or more inhaled bronchodilators. It may be necessary to use a 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. The doctor may recommend that trying inhaled steroids for a trial period of 6 weeks to 3 months to see if the medicine is helping with the breathing problems.

Flu shots

The flu (influenza) can cause serious problems in people with COPD. Flu shots can reduce the chance of getting the flu. It is a good idea to get a flu shot every year.

Pneumococcal vaccine

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.

Therapies

Pulmonary Rehabilitation

Pulmonary rehabilitation (rehab) is a coordinated program of exercise, disease management training, and counseling that can help with staying active and carrying out day-to-day activities. What is included in pulmonary rehab program will depend on what each person needs. It may include exercise training, nutrition advice, education about the 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 an individual program. Pulmonary rehab programs can include some or all of the following aspects.

Medical evaluation and management

To decide what will be needed during a pulmonary rehab program, a medical evaluation will be done. This may include getting information on health history and what medicines are being taken, doing a physical exam, and learning about symptoms. A spirometry measurement may also be done before and after taking a bronchodilator medicine.

Patients work with a pulmonary rehab team to set goals for the program. These goals will look at the types of activities that each person want to do. For example, one person may want to take walks every day, do chores around the house, and visit with friends. These things will be worked on in the pulmonary rehab program.

Exercise training

The program may include exercise training. This training includes teaching exercises to help the arms and legs get stronger. It may also be helpful to learn breathing exercises that strengthen the muscles needed for breathing.

Education

Many pulmonary rehab programs have an educational component that helps patients learn about their disease and symptoms, commonly used treatments, different techniques used to manage symptoms, and what can be expecedt 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 breathing to carry out everyday activities; or (3) a respiratory therapist to learn about breathing techniques and how to do respiratory treatments.

Patients will usually talk with the pulmonary rehab team at different times during the program to go over the goals that have been set and see if goals are being met. For example, if the goal is to walk every day for 30 minutes, the patient will talk to members of the pulmonary team and tell them how often they are walking and for how long. The team is interested in helping patients reach their goals.

Oxygen Treatment

In cases of severe COPD and low levels of oxygen in the blood, the pateint may not be able to get enough oxygen on their own. The doctor may recommend oxygen therapy to help improve shortness of breath. It may also be necessary to carry 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

Surgery

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:

• Bullectomy. 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.

Prevention

For smokers, the most important thing that they can do to stop more damage to the lungs is to quit smoking. Many hospitals have smoking cessation programs or can refer one.

It is also important to stay away from people who are smoking and places where 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, it is important to stay in the house when the outside air quality is poor.

Living With Chronic Obstructive Pulmonary Disease

Although there is no cure for chronic obstructive pulmonary disease (COPD), symptoms can be managed, and damage to the lungs can be slowed. For smokers, quitting is the most important thing that can be to help the lungs. . It may also be necessary to try and stay away from people who are smoking or places where there is smoking.

It is important to keep the air in the home clean. Here are some things that may help in the home:

• Keep smoke, fumes, and strong smells out of the home.
• If the home is painted or sprayed for insects, have it done when it will be possible stay away from the home.
• Cook near an open door or window.
• If heating with wood or kerosene, keep a door or window open.
• Keep windows closed and stay at home when there is a lot of pollution or dust outside.

If taking medicines, take them as ordered and make sure to refill them so that they do not run out.

See the doctor at least two times a year, even if feeling fine. Make sure to bring a list of medicines being taken to the doctor visit.

Ask the doctor or nurse about getting a flu shot and pneumonia vaccination.

Keep strong by learning breathing exercises and walking and exercising regularly.

Eat healthy foods. Ask family members to help with buying and fixing healthy foods. Eat lots of fruits and vegetables. Eat protein food like meat, fish, eggs, milk, and soy.

If the doctor diagnoses severe COPD, there are some things that can be done to get the most out of each breath. Make life as easy as possible at home by:

• Asking friends and family for help.
• Doing things slowly.
• Doing things sitting down.
• Putting important things 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 reach things.
• Keeping clothing loose.
• Wearing clothes and shoes that are easy to put on and take off.
• Asking for help moving things around in the house so that it will not be necessary to climb stairs as often.

If it is becoming more difficult to breathe, if coughing has gotten worse, coughing up more mucus, or if there are signs of infection (such as a fever and feeling poorly), it will be necessary to call a doctor right away. The doctor may do a spirometry test, blood work, and a chest x ray. The doctor may also:

• Order antibiotics, which are medicines that help fight off infection
• Change the type and dosage of the bronchodilator and glucocorticosteroid medicines that are being taking
• Order oxygen or increase the amount of oxygen that is currently being used

It is helpful to have certain information on hand in case it is necessary to go to the hospital or doctor right away. Plan now to make sure to have:

• The phone numbers for the doctor, hospital, friends and family who can help, if necessary
• Directions to the hospital and doctor's office
• A list of the medicines being taken

Get emergency help if:

• It is hard to talk or walk.
• The heart is beating very fast or irregularly.
• The lips or fingernails are gray or blue.
• Breathing is fast and hard, even when using medicines as prescribed.

Related Problems

People with chronic obstructive pulmonary disease (COPD) often have symptoms that suddenly get worse. When this happens, they have a much harder time catching their breath. They may also have chest tightness, more coughing, change in sputum, and a fever. It is important to call the doctor if you have any of these signs or symptoms.

The doctor will look at things that might be causing these signs and symptoms to suddenly worsen. Sometimes the signs and symptoms are caused by a lung infection. He or she may recommend taking an antibiotic medicine that helps fight off the infection.

The doctor may also recommend additional medicines to help with breathing. These medicines include bronchodilators and glucocorticosteroids.

The doctor may recommend that you spend time in the hospital if:

• There is a lot of difficulty catching your breath.
• It is difficult to talk.
• The lips or fingernails turn blue or gray.
• Mental alertness decreases.
• The heartbeat is very fast.
• Home treatment of worsening symptoms doesn't help.

Clinical Trials

• Chronic Obstructive Pulmonary Disease Clinical Trials
• Current Research (National Institutes of Health)

Other Resources

• For information on how to quit smoking, visit the Web site of the U.S. Office of the Surgeon General
• Learn About COPD
• Chronic Obstructive Pulmonary Disease (COPD) Data Fact Sheet
• Chronic Obstructive Pulmonary Disease (MedlinePlus)
• Tobacco Cessation Guideline (U.S. Office of the Surgeon General)