The main difference between COPD and asthma is that asthma is usually completely reversible. This means that with treatment, a person with asthma can have near-normal lung function and be free of symptoms between episodes / flare-ups. Asthma episodes with wheezing, shortness of breath, chest tightness and cough often have triggers that can be identified easily. These triggers can be seasonal or other allergens, airborne irritants such as smoke or dust, strong odors or chemicals, cold air or exercise.
 

COPD is characterized by airflow obstruction that is only partially reversible, or completely non-reversible.  People with partial reversibility don’t usually experience the same level of improvement with medications as do people with asthma. A person with COPD will always have a lung function results lower than normal, even when not sick with an episode / flare-up (exacerbation).  As indicated by the name, COPD is a chronic disease. It is always there even when you’re feeling well. It does not go away.


Another difference is that although episodes /flare-ups, (exacerbations) in people with COPD can be brought on by irritants in the air, they are more commonly caused by bacteria or virus in the respiratory tract.


It is sometimes thought that an easy way to tell the difference between COPD and asthma is the age when a diagnosis is made – that asthma is most often diagnosed in childhood, adolescence, or early adulthood while COPD is diagnosed later in life. But this is not always the case. It’s common for the genetically-inherited cause of COPD, Alpha-1 Antitrypsin Deficiency, to be mistaken for asthma in a younger person.

Is it possible to be diagnosed with both COPD and asthma?
Yes. It is not unusual for a person to have all these things going on in the lungs: Damage of the alveoli with over-inflation, frequent cough with increased mucus production, and reversible airway constriction.  It is for this reason that people with COPD may be on several inhaled medications and / or combination meds. Each class of medication works to open the airways of the lungs in its own way.  


Jane M. Martin is a licensed respiratory therapist, teacher and the founder and director of http://www.Breathingbetterlivingwell.com and the author of Live Your Life With COPD: 52 Weeks of Health, Happiness and Hope and Breathe Better, Live in Wellness: Winning Your Battle Over Shortness of Breath.