When Asthma and COPD Overlap
When a person with asthma or chronic obstructive pulmonary disease (COPD) is experiencing shortness of breath or another symptom, they may not think they are suffering from more than one chronic lung disease. However, according to the Global Initiative for Chronic Obstructive Lung Disease, 15 to 55 percent of patients with variation by gender and age may have asthma-COPD overlap syndrome (ACOS), a disease that includes components of both asthma and COPD.
Asthma is a lifelong inflammatory disease that affects the airways in your lungs. COPD, including emphysema and chronic bronchitis, is also an inflammatory disease that causes airflow blockage and breathing-related problems. ACOS is usually associated with asthma and COPD and is described as persistent airflow limitation. People at risk for ACOS are typically those with asthma who smoke or heavy smokers with genes that can cause an allergic inflammatory response to inhaled particles. However, more research is needed to be able to fully characterize the disease.
"We're working to learn more and more about the different subgroups (called phenotypes) of asthma and COPD and their different pathways (or endotypes)," said Albert A. Rizzo, M.D., senior medical advisor to the American Lung Association.
Symptoms of ACOS are likely to include chest tightness, coughing with a mixture of saliva and mucus, and wheezing. It is reported that people diagnosed with ACOS experience their symptoms more frequently and have reduced lung function. These patients are also likely to make more hospital visits.
"It is crucial to better identify ACOS patients to get them on the right therapies sooner, which will be important in relieving their symptoms. Thus, this may translate into fewer flare-ups that appear to be present in patients identified as having an overlap of asthma and COPD," Dr. Rizzo explained.
If you or someone you love suspects that they may have ACOS, a physician should perform a pulmonary function test or a bronchodilator reversibility test. Both tests use a spirometer to determine how well the lungs are working. See a pulmonary function test in action on our YouTube channel. We also have tips and a worksheet that will help make your doctor's visit most productive.
We will continue to work toward understanding ACOS and providing resources for asthma and COPD patients. One such way is through our Airways Clinical Research Center (ACRC). The ACRC is the nation’s largest not-for-profit network of clinical researcher centers dedicated to asthma and COPD treatment research. Patients with either asthma or COPD are encouraged to participate in clinical trials that will help us better understanding both asthma and COPD and thus, develop better treatments for these chronic lung diseases.