COPD and asthma are diseases that involve different types of inflammation in the airways, Dr Christopher Worsnop, a respiratory and sleep physician at Austin Hospital in Melbourne, says.
COPD (chronic obstructive pulmonary disease) is primarily caused by cigarette smoke and induces a neutrophilic-type inflammation in the airways.
“We don’t really know what causes asthma,” says Dr Worsnop. “It’s a combination of genetics and environmental exposures, but it’s a predominantly allergic oreosinophilic type of inflammation in the airways.”
“Clinically, the difference is that COPD tends to come on later in life, so young and middle-aged adults who have been exposed to cigarette smoke or some other type of toxic gas and their symptoms come on very gradually over time, so breathlessness, cough, sputum production, and also a limitation in activity because patients are fearful of developing a symptom of breathlessness.
“Whereas in asthma, it tends to occur earlier in life so often it occurs in children for the first time, although it can occur in adults for the first time as well. The symptoms are much more variable over time. They tend to fluctuate a lot, particularly in response to typical asthma triggers, like exposure to respiratory viruses, pollens, dusts, exercise, cold dry air, things like that.”