What causes COPD and How?
National Allergy Asthma Bronchitis Institute,
We are in the midst of an epidemic of chronic obstructive pulmonary disease (COPD) without being aware of it. The disease can be minimally expressed as progressive narrowing of the distal airways of the lungs. The disease goes vastly unnoticed as the occlusion of the distal airways does not produce much symptom till the end. Secondly, as COPD is usually a disease of the smokers, they tend to ignore the developing shortness of breath lest they need to give up their addicting stuff. Thirdly, unless we do pulmonary function testing (spirometry), it’s very difficult to document and convince the patient about the severity of the airway obstruction. All these lead to delayed and ineffective management. COPD is important not only because of the scale of the epidemic, but also to the fact that most productive years of the person and society are being wasted because of the aliment.
It is well established that tobacco smoke exposure is the most significant risk factor for developing COPD. The more years you smoke and the more packs you smoke, the greater is your risk. In the developing world, COPD also occurs in women exposed to fumes from burning fuel for cooking and heating in poorly ventilated homes. People exposed to large amounts of secondhand smoke are also at risk. People who are consistently exposed to both wood smoke and tobacco smoke are at a greater risk for developing COPD.
The combination of asthma, a chronic airway disease, and smoking increases the risk of COPD even more. Long-term exposure to chemical fumes, vapors and dusts in the workplace can irritate and inflame your lungs.
In recent new research, investigators have shown that the cells that line the airways also can respond to viruses in a way that leads to long-term lung inflammation and mucus production that are typical of COPD. Ageing and genetic predisposition may also contribute.
Prolonged exposure to lung irritants can lead to inflammation in bronchial tubes as a result of which, the airways produce more mucus than they normally would. Inflammation and excess mucus cause coughing and narrow the airways. It is hard to breathe through the narrow airways and more air comes in than what goes out leading to air trapping inside the lungs. Recurrent chest infections further worsen the process.
Damage to the elastic fibers in the lungs make the lung like an over stretched balloon. This voluminous but ineffective organ of respiration causes breathlessness on exertion.