Why is emphysema a COPD?

Emphysema is a type of chronic obstructive pulmonary disease (COPD) because it causes airflow limitation in the lungs that is not fully reversible. In emphysema, the alveoli in the lungs are damaged and destroyed, which leads to a loss of elasticity and an increase in airway resistance. This makes it difficult for air to move in and out of the lungs, resulting in shortness of breath, wheezing, and coughing.

The other main type of COPD is chronic bronchitis, which is characterized by inflammation and mucus production in the bronchi. While emphysema and chronic bronchitis are often thought of as separate conditions, they often occur together and are referred to as COPD.