While asthma usually first appears in childhood, COPD is normally diagnosed during middle or later life. Asthma is characterized by hyperresponsiveness of the airways, airway inflammation and airflow obstruction which may be relieved spontaneously or with medication. Yet, between exacerbations, asthma, in most cases, is completely reversible. COPD, however, is a chronic, progressive disease characterized by airway obstruction which is NOT fully reversible. This means that people with COPD are always, to some degree, symptomatic, while people with asthma, don't usually have symptoms between asthma attacks.
Asthma symptoms are said to be brought on by certain "triggers," such as allergens, like pet dander and pollen, or airway irritants, such as cold air or strong odors. Asthma can also be brought on by lung infections. The number one cause of COPD, however, is smoking, with secondhand smoke, air pollution and workplace exposure also placing people at risk for the disease. In addition, lung infections do not cause COPD, but can lead to a worsening of symptoms, or COPD exacerbation.
Both asthma and COPD are treated with bronchodilator inhalers which work to relax the airways, and steroids to reduce airway inflammation. Steroids play a much bigger role, however, in the treatment of asthma than they do in COPD. But, does having asthma place you at risk for developing COPD? Results from one study suggests that it does.
In a 20-year, follow-up study published in Chest, compared to non-asthmatics, patients who had asthma had a 10-times-higher risk for acquiring symptoms of chronic bronchitis, a 17-times-higher risk of receiving a diagnosis of emphysema, and a 12.5-times-higher risk of meeting criteria necessary to diagnose COPD. This was even after adjustments were made for smoking history and other potential confounders. So, although asthma and COPD are distinct entities, and have different physiological features and risk factors, having asthma is significantly associated with an increased risk for the development of COPD.
So, what can you do with this information? That's simple. If you are concerned that you may have asthma on top of COPD, talk with your healthcare provider about being tested for asthma.
For more information about asthma, read:
What is Asthma?
What is Asthma?
Graciela E. Silva, MPH, Duane L. Sherrill, PhD, Stefano Guerra, MD, PhD, MPH, and Robert A. Barbee, MD, FCCP. Asthma as a Risk Factor for COPD in a Longitudinal Study.
CHEST July 2004 vol. 126 no. 1 59-65.
Graciela E. Silva, MPH, Duane L. Sherrill, PhD, Stefano Guerra, MD, PhD, MPH, and Robert A. Barbee, MD, FCCP. Asthma as a Risk Factor for COPD in a Longitudinal Study. CHEST July 2004 vol. 126 no. 1 59-65.