Asthma is a disease that results in chronic inflammation of respiratory pathways, causing them to become narrow and obstructing airflow. Symptoms of asthma include raspy breathing, inability to inhale and exhale comfortably, a severe tightening of the chest muscles and uncontrollable fits of coughing.
Chronic obstructive pulmonary disease, on the other hand, is a condition which prevents the patient from breathing normally due to his/her lungs responding adversely to harmful vapours or particles.

The most notable difference between asthma and chronic obstructive pulmonary disease is the way in which they cause the respiratory system to become inflamed. In the case of asthma, it is mostly eosinophilic, driven by CD4. In case of chronic obstructive pulmonary disease, the inflammation is neutrophilic, driven by CD8. Due to this distinction, the diseases respond differently to the same type of medication upon administration, despite their symptoms appearing to be similar at first glance. Inhaled corticosteroids can be used to treat asthmatic swellings, but they cannot be used to treat the swellings caused by chronic obstructive pulmonary disease, due to their different natures. However, it cannot be ignored that many similarities also exist between the two diseases, making their diagnosis a challenge in many cases.