What is chronic obstructive pulmonary disease?

Chronic obstructive pulmonary disease (COPD) is a group of lung diseases that makes it hard for a person to breathe. In COPD, airflow through the airways (bronchial tubes) within the lungs is partially blocked, resulting in difficulty breathing. As the disease progresses breathing becomes more difficult, and it may become difficult to carry out everyday activities. COPD is the fourth leading cause of death in the United States and Canada.

COPD develops over many years (sometimes 10 to 30 years) and is most commonly diagnosed in people over the age of 60. Because of this, COPD generally is considered a disease of older adults. COPD is sometimes called chronic obstructive lung disease (COLD) or chronic airflow obstruction (CAO).

What causes COPD?

COPD is a group of lung diseases. The two diseases that generally are associated with COPD are chronic bronchitis and emphysema . Although a person with COPD sometimes can have either chronic bronchitis or emphysema, he or she often has a mixture of the symptoms of both diseases.

COPD is most often caused by smoking cigarettes. Nearly all people with COPD (80% to 90%) have a history of significant cigarette use, and research supports the fact that smoking cigarettes clearly increases the risk of developing COPD. Interestingly, only up to 20% of long-term smokers will develop COPD; this is likely because genetic factors also influence a person's risk of developing COPD.

Other lung irritants that are inhaled over a long period of time—such as industrial dust and chemical fumes—are also believed to cause COPD.

Some people may be more susceptible to developing COPD than others; this is also believed to be because of genetic factors. A low birth weight and repeated lung infections may also make a person more susceptible to COPD.

What are chronic bronchitis and emphysema?

Both chronic bronchitis and emphysema affect the lungs and how well you can breathe.

In chronic bronchitis, inflammation occurs in the bronchial tubes. The inflammation may cause a narrowing of the bronchial tubes, which makes it hard to breathe. A chronic cough that brings up sputum (a productive cough) usually is present.

In emphysema, lung tissue and the tiny air sacs (alveoli) at the end of the airways are damaged. When these tiny air sacs are damaged, air is trapped in the lungs. This leads to shortness of breath.

See an illustration of bronchitis and emphysema .

What is a COPD exacerbation?

A COPD exacerbation is a rapid increase in shortness of breath that develops in some who have COPD. An exacerbation can be a serious problem and may become life-threatening. With prompt and effective treatment, most people recover and return to the same level of breathing difficulty they had before the exacerbation

What happens when I have COPD?

The symptoms you experience depend on whether your COPD is mainly chronic bronchitis or emphysema.

If you have the chronic bronchitis component of COPD, you usually will first notice a cough that brings up (sputum) mucus. If you have primarily emphysema, you may not have much cough and may not have symptoms until shortness of breath appears.

As COPD progresses, lung function declines. You begin to experience increased shortness of breath during exertion. You may have times when your shortness of breath may suddenly get much worse (a COPD exacerbation). In severe COPD you may become out of breath with little or no exertion and find it difficult to perform everyday activities.

How severe the condition is and how quickly it progresses varies from person to person.

Although there is no way to reverse the damage COPD causes, stopping smoking can slow the decline in lung function. If you continue to smoke, the disease will progress more quickly. In some people, oxygen therapy can prolong life in cases of severe COPD.

COPD may also lead to complications such as lung infections, depression, weight loss, and a heart problem called cor pulmonale .

How is COPD diagnosed?

A medical history, physical exam, and most importantly lung function tests are used to diagnose COPD.

Early detection of COPD is very important. The sooner a person quits smoking and avoids other environmental factors that contribute to COPD, the better the chances are of slowing damage to the airways and lungs.

How is COPD treated?

There is no cure for COPD at this time. Damage to the airways and lungs cannot be reversed once it has occurred. The focus is on slowing the progression of the disease and relieving symptoms. The best way to slow the disease is to stop smoking. Medications may reduce or relieve your symptoms. In you have severe COPD, a pulmonary rehabilitation program that includes counseling, education, exercise, breathing exercises, and nutrition may also help reduce your symptoms. Oxygen therapy may be needed when oxygen levels in the blood are low.

How do I live with COPD?

The lung damage that causes symptoms in COPD cannot be reversed. Once you have severe COPD, you will probably have to modify your lifestyle to make the most use of your remaining lung function. You should also remove factors that can rapidly worsen your condition, such as smoking.

The severe shortness of breath found in severe COPD may mean building "rest breaks" into your day and pacing yourself. You may be asked to participate in pulmonary rehabilitation, which is a structured and supervised program including counseling, education, exercise, breathing exercises, and nutritional guidance. You may have to take medications regularly to help control your symptoms.

If you have severe COPD, you may want to talk about end-of-life issues with your doctor and family. All of the people involved in your care should be aware of your decisions regarding medical care at later stages of the disease. For more information, see the topic End-of-Life Care in Related Information.