CLRD vs. COPD
The term COPD (chronic obstructive pulmonary disease) is sometimes used interchangeably with CLRD (chronic lower respiratory disease). In fact, CLRD is a slightly broader category. It includes asthma as well as COPD.
COPD itself comprises two main diseases: chronic bronchitis and emphysema. While these diseases are separate and distinguished, patients with COPD often suffer from more than one of them at once. For instance, the majority of patients have both chronic bronchitis and emphysema to differing degrees. This is because chronic bronchitis usually progresses into emphysema. According to the CDC, in 2016 8.9 million Americans were diagnosed with chronic bronchitis and 3.5 million with emphysema.