COPD

Source: MedlinePlus Health Topics, U.S. National Library of Medicine

Last synced 8/10/2026Status: primary verified

What is COPD (chronic obstructive pulmonary disease)? COPD (chronic obstructive pulmonary disease) is a group of lung diseases that make it hard to breathe and get worse over time. Normally, the airways and air sacs in your lungs are elastic or stretchy. When you breathe in, the airways bring air to the air sacs. The air sacs fill up with air, like a small balloon. When you breathe out, the air sacs deflate, and the air goes out. If you have COPD, less air flows in and out of your airways because of one or more problems: The airways and air sacs in your lungs become less elastic 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 and can become clogged What are the types of COPD (chronic obstructive pulmonary disease)? COPD includes two main types: Emphysema affects the air sacs in your lungs, as well as the walls between them. They become damaged and are less elastic. Chronic bronchitis , in which the lining of your airways is constantly irritated and inflamed. This causes the lining to swell and make mucus. Most people with COPD have both emphysema and chronic bronchitis, but how severe each type is can be different from person to person. What causes COPD (chronic obstructive pulmonary disease)? The cause of COPD is usually long-term exposure to irritants that damage your lungs and airways. In the United States, cigarette smoke is the main cause. Pipe, cigar, and other types of tobacco smoke can also cause COPD, especially if you inhale them. Exposure to other inhaled irritants can contribute to COPD. These include secondhand smoke , air pollution , and chemical fumes or dusts from the environment or workplace. Rarely, a genetic condition called alpha-1 antitrypsin deficiency can play a role in causing COPD. Who is at risk for COPD (chronic obstructive pulmonary disease)? The risk factors for COPD include: Smoking. This is the main risk factor. Up to 75% of people who have C

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This information is for general education and is not medical advice. Always talk to a licensed U.S. clinician about your situation, medications, or treatment decisions.