s, there is persistent inflammation and eventual scarring of the bronchial tubes. The inflammation causes excessive production of mucus and swelling of the bronchial walls. The chief cause of chronic bronchitis, however, is cigarette smoking, including exposure to secondhand smoke. Chronic bronchitis is often not treated properly until it has reached an advanced stage because sufferers do not realize its seriousness until their lungs have already been damaged. By this time, the lining of the bronchial tubes has thickened due to the persistent inflammation, excess mucus is constantly being produced, there is much coughing, airflow is increasingly hampered, and respiratory infections occur with greater frequency due to the ideal breeding conditions of the bronchi. Overall, the 10‐year mortality rate following a diagnosis of chronic bronchitis is about 50 percent.
Emphysema. Emphysema is a pathological definition: abnormal permanent enlargement of the air spaces at the ends of the bronchioles, accompanied by the destruction of their walls. Most emphysema is caused by smoking. ATT, a protein produced by the liver, can be deactivated by cigarette smoke and affect the elasticity and functioning of the lungs, leading to the gradual development of emphysema. The initial symptom of emphysema is shortness of breath (dyspnea). A cough might also be present, as chronic bronchitis often precedes emphysema. As the disease progresses, even a short walk can result in difficulty in breathing.
Millions of Americans suffer from COPD so severely that the illness interferes with their daily activities, and more than half report that their COPD limits their ability to work. Nearly half report that they get short of breath while doing light housework or washing and dressing. Nearly one-third of COPD sufferers get short of breath while talking. About 25 percent of COPD patients report difficulty breathing even when sitting down or lying still and describe themselves as invalids. About half of COPD sufferers said their disease limited their social activities and affected their family activities. The psychological effect of COPD on patients was devastating. Over half of those surveyed said they felt panic when they could not get their breath or felt they were not in control of their breathing. Two‐thirds said they expected their condition to get worse. Overall, the median survival rate for patients who have lost two-thirds of their lung function is 10 years.