Though asthma and bronchitis have many symptoms in common. But a basic difference between the two diseases is as follows: Asthma is a disease with a genetic mode of inheritance which gets triggered upon exposure to certain allergens. Whereas COPD is a disease which is acquired during a lifetime due to exposure to environmental factors like smoking, biomass fuel smoke etc. Also, asthma has an early onset i.e it is seen in the younger individual. On the contrary, COPD is mostly observed in elderly individuals (40 yrs and above). Individuals suffering from asthma are asymptomatic in between the acute attacks of the disease. Whereas in COPD the patient has a constant experience of dyspnea during the entire duration.