Asthma is caused by the constriction of the respiratory pathways, making breathing very difficult for the patient. Due to the restricted airflow, a wheezing sound often ensues during asthmatic breathing. It is a condition many people are inherently born with, and an asthmatic attack is triggered whenever the individual is exposed to certain allergens. Mucus may or may not be produced as a result of asthma.

On the other hand, bronchitis manifests itself as a swelling of the bronchial tubes within the lungs. One of the most visible signs of bronchitis is a signature cough developed by a long-time patient of it. Bronchitis is inflammation of the bronchi. The long-suffering with bronchitis other has a cough, accompanied by copious amounts of mucus produced in the lungs. Bronchitis may occur as a result of regular smoking habits, influenza or cold-related diseases which can cause lung infections. Bronchitis can evolve into pneumonia over time if left unchecked.

A certain variant of asthma, occupational asthma, can be picked up from one's work environment due to the presence of certain attack-inducing substances there, but the same cannot be said for bronchitis, which can develop due to entirely different causes.