Chronic Obstructive Pulmonary Disorder (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 tubes, or airways.

The airways are shaped like an upside-down tree with many branches. At the end of the branches are tiny air sacs called alveoli.

The airways and air sacs are elastic. When you breathe in, each air sac fills up with air like a small balloon. When you breathe out, the air sac deflates 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 (swollen).
• The airways make more mucus than usual, which tends to clog the airways.

Outlook

COPD is a major cause of disability, and it's the fourth leading cause of death in the United States. More than 12 million people are currently diagnosed with COPD. An additional 12 million likely have the disease and don't 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 people. 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 obstructive airway disease
• Chronic obstructive bronchitis
• Chronic obstructive lung disease
• Emphysema

What Causes COPD?

Most cases of COPD develop after long-term exposure to lung irritants that damage the lungs and the airways.

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. Secondhand smoke—that is, smoke in the air from other people smoking—also can irritate the lungs and contribute to COPD.

Breathing in air pollution and chemical fumes or dust from the environment or workplace also can contribute to COPD.

In rare cases, 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.

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 get 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 air pollution and chemical fumes and dust from the environment or workplace.

Most people who have COPD are at least 40 years old when symptoms begin. Although it isn't common, 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?

The signs and symptoms of COPD include:

• An ongoing cough or a cough that produces large amounts 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

These symptoms often occur years before the flow of air into and out of the lungs declines. However, not everyone who has these symptoms 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 determine if you have COPD.

If you have COPD, you may have frequent colds or flu. If your COPD is severe, you may have swelling in your ankles, feet, or legs; a bluish color on your lips due to low levels of oxygen in your blood; and shortness of breath.

COPD symptoms usually slowly worsen over time. At first, if 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 bad enough to see a doctor. For example, you may get short of breath during physical exertion.

How severe your symptoms are depends on how much lung damage you have. If you keep smoking, the damage will occur faster than if you stop smoking. In severe COPD, you may have other symptoms, such as 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.

He or she may ask whether you smoke or have had contact with lung irritants, such as air pollution, chemical fumes, or dust. If you have an ongoing cough, your doctor may ask how long you've had it, how much you cough, and how much mucus comes up when you cough. He or she also may ask 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.

You also may need 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 can deliver oxygen to your blood.

The main test for COPD is spirometry. Other lung function tests, such as a lung diffusing capacity test, also may be used.

Spirometry

During this painless test, a technician will ask you to take a deep breath in and then 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 of your lungs.. It also measures how fast you can blow air out of your lungs.

Spirometry

The photo 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 exhaled and how fast it was 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 long before its symptoms appear. Doctors also may use the results from this test 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. These tests include:

• A chest x ray or chest computed tomography (CT) scan. These tests create pictures of the structures inside your chest, such as your heart and lungs. 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 test can help find out how severe your COPD is and whether you may need supplemental oxygen therapy.

Top of Page

Previous