Chronic Obstructive Pulmonary Disease (COPD)

What Increases Your Risk

Risk factors for chronic obstructive pulmonary disease (COPD) include those you can control, such as smoking, and others that you cannot control, such as inherited factors (genes).

Risk factors you can control

Tobacco smoking is the most important risk factor for COPD. In comparison, other risk factors are minor.

• At least 10% to 15% of all cigarette smokers develop COPD with symptoms; some studies indicate up to 50% of long-term smokers older than age 45 develop COPD.^{3, 2} Inherited factors (genes) and exposure factors probably determine which smokers develop COPD.
• Pipe and cigar smokers have less risk of developing COPD than cigarette smokers but still have greater risk than nonsmokers.
• The risk of developing COPD increases with both the amount of tobacco you smoke per day and the number of years you have smoked.

It is not yet known whether secondhand smoke can lead to COPD. However, people who are exposed to secondhand smoke for a long time are more likely to have breathing problems and respiratory diseases.

See a graph on how smoking affects the ability to breathe.

Risk factors you can partially control include:

• Outside air pollution. Air pollution may make COPD worse if you already have it and may increase the risk of a COPD exacerbation—a rapid, sometimes sudden, and prolonged worsening of symptoms (cough, amount of mucus, and/or shortness of breath). Try not to be outside when air pollution levels are high.
• Indoor air pollution. Have adequate ventilation in your home to avoid indoor air pollution.
• Occupational hazards. If your work exposes you to chemical fumes or dust, use safety equipment to reduce the amount of these irritants you breathe. Coal miners may be at risk for black lung disease.
• Frequent, severe respiratory infections. Repeated lung infections, especially in childhood, may make you more likely to develop COPD later in life.

Risk factors you cannot control include:

• Family history of COPD. Some people may be more at risk than others for developing the disease, especially if they have low levels of the protein alpha1-antitrypsin (alpha1-antitrypsin deficiency).
• Low birth weight. People born at a low birth weight are more likely than those of normal birth weight to have smaller lungs and therefore to have reduced lung function.
• Asthma. People with asthma or with airways that narrow in response to environmental triggers, such as pollen, are more likely to develop COPD.