2006 ICD-9-CM Volume 1 Diagnosis Codes Home > Diseases Of The Respiratory System 460-519 > Chronic Obstructive Pulmonary Disease And Allied Conditions 490-496 > ICD-9-CM Diagnosis 492 Emphysema A subcategory of chronic obstructive pulmonary disease (COPD). It occurs in people who smoke and suffer from chronic bronchitis. It is characterized by inflation of the alveoli, alveolar wall damage, and reduction in the number of alveoli, resulting in difficulty breathing. Alveoli are the vital lung structures where the transfer of oxygen and carbon dioxide takes place. -- 2004 Pulmonary emphysema is a disorder affecting the alveoli (tiny air sacs) of the lungs. The transfer of oxygen and carbon dioxide in the lungs takes place in the walls of the alveoli. In emphysema, the alveoli become abnormally inflated, damaging their walls and making it harder to breathe. People who smoke or have chronic bronchitis have an increased risk of emphysema. A subcategory of CHRONIC OBSTRUCTIVE PULMONARY DISEASE. The disease is characterized by anatomic alterations of the lungs, such as the enlargement of airspaces and destruction of alveolar walls. 492 is a non-specific code that cannot be used to specify a diagnosis ICD-9-CM Diagnosis 492.0 Emphysematous bleb 492.0 is a specific code that can be used to specify a diagnosis 492.0 contains 9 index entries ICD-9-CM Diagnosis 492.8 Other emphysema A pathological accumulation of air in tissues or organs. 492.8 is a specific code that can be used to specify a diagnosis 492.8 contains 19 index entries