Do I Have Asthma or COPD or Both?
by Helen Sorenson, MA, RRT, CPFT, FAARC
While having lunch, Susan noted that her friend Marsha took out an inhaler and used it. Susan was astonished to see that it was the same inhaler, same medication, that she used. Perplexed, she asked Marsha, “Do you have COPD?”
Marsha looked surprised and replied, “No, I have asthma — why do you ask?”
The confusion between these two conditions is not uncommon, as some of the same medications are used to treat them and some of the symptoms seem similar. But they are two different diseases.
There are several ways to distinguish asthma from COPD. While not an exact science, the following chart may help you see where your breathing difficulties fit best —
Table adapted from Petty TL and Seebass JS. Pulmonary Disorders of the Elderly 2007: p. 91.
The differences in these diseases stem in part from the fact that the causes are not the same. Asthma symptoms are generally caused by inflammation (swelling and irritation) of the airways. COPD, which includes emphysema, is caused more by damage to the airways and the small air sacs that are important for gas exchange in the body.
As noted in the table, asthma and allergies are closely related. The most common symptoms are coughing, wheezing, and shortness of breath. But while individuals with COPD are less likely to have allergies, they also experience coughing, wheezing, and shortness of breath. The challenge for physicians arises when a patient has both asthma and COPD.
Because some of the medications used for asthma are very different from those used to treat COPD, it is important to have a correct diagnosis. According to doctors and respiratory therapists, a breathing test called spirometry should be used to determine which disease you have.
Spirometry involves breathing out hard and fast into a machine for 3-5 seconds. The machine records how much air you exhale in one second and this is called your “FEV1”. After the breathing test you will be given a medicine called a bronchodilator to inhale. Bronchodilators relax the airways. After about 15 minutes you will be asked to repeat the breathing test. If your FEV1 improves by a certain pre-determined amount, you have asthma. If it does not, asthma is unlikely.
Even if you have been diagnosed with COPD, it is still a good idea to have this test performed, as many people do have both diseases!
Since a correct diagnosis is so important, speak with your physician if you are unsure what is causing your symptoms of coughing, wheezing, and shortness of breath, Ask if he or she will order a spirometry test. Knowing what is causing your disease is the best way to treat — and perhaps prevent — those troublesome symptoms.
Helen Sorenson is a respiratory therapist and Fellow of the American Association for Respiratory Care from San Antonio, TX, where she currently serves as adjunct faculty in the department of respiratory care at the University of Texas Health Science Center at San Antonio.