Chronic Obstructive Pulmonary Disease (COPD) was estimated to be the twelfth leading cause of death worldwide in 1990. Of all the major diseases, COPD is one for which the burden is growing fastest. By 2020 it is expected to be the third leading cause of death and fifth leading cause of disability. COPD patients often have few complaints despite suffering considerable disability. As a result, although COPD can be easily diagnosed, it frequently is...