What causes COPD?
COPD is caused by long-term exposure to gases or particles that irritate your lungs. In 90% of cases, this is from cigarette smoke. Smoking inflames your lungs and over a long period of time they can become damaged and scarred. This can lead to the development of emphysema or chronic bronchitis, conditions that cause airway obstruction.
Emphysema cause destruction of the fragile walls and air sacs (alveoli) in your lungs. This makes the thin airways in your lungs collapse, making it hard to breath out.
Chronic bronchitis is caused by inflammation of your bronchial tubes (tubes that carry air to and from your air sacs). The tubes narrow, and your lungs produce mucus, which further blocks your airways.
If you have COPD you could have one or both of these conditions. When you breathe out, your lungs rely on the natural elasticity of both the air sacs and bronchial tubes to help push air out of your body. COPD causes your lungs lose their elasticity, making it harder to exhale.
Other causes of COPD include passive smoking and exposure to dust, fumes and air pollution. You may be particularly at risk of COPD if you work with cadmium, coal, isocyanates or grains, which generate a lot of dust during processing. People who have asthma and smoke are also more at risk of developing COPD. Some genetic factors may increase susceptibility to the disease, including a rare deficiency of alpha-1-antitrypsin, a protein that helps to protect your lungs from enzyme damage. However, this only causes COPD in about 1% of patients.