Chronic bronchitis, as its name suggests, is often a longstanding condition that you will likely deal with for many years if not your entire life. As such, I would recommend talking to your primary doctor
or a pulmonologist
(a lung specialist) in order to fully understand this condition.
Chronic bronchitis refers to a longstanding inflammation of your medium to large airways. It, along with emphysema, is part of spectrum of disease cause Chronic Obstructive Pulmonary Disease or COPD
. This inflammation of your airways will cause a productive cough (that is you make sputum) at least three months of a year for two consecutive years. Therefore if you have gotten "seasonal" cough for two straight years then your diagnosis is likely accurate.
As for what causes the inflammation, in almost all cases it is from smoking. If you are a smoker, this is undoubtedly the cause and you must stop. Second hand smoke can also exacerbate it . The air outside, unless it is toxic smog, is unlikely to be the major culprit.
This inflammation can cause your airways to become smaller and eventually leave you having difficulty breathing. It also makes you more susceptible to infection of the airways.
Chronic bronchitis is caused in most cases by smoking. You should discuss this with your primary doctor.