What is Chronic Bronchitis?

Chronic bronchitis is defined clinically as "a cough productive of sputum on most days, for at least three months of each year, in more than one consecutive year".

It is characterised by a persistent inflammation of the bronchial walls (large airways of the lungs), with oedema (swelling) of the lining and an increased production of mucus, causing cough and sputum most of the time. This tends to “clog up” the airways, and the process can lead to the eventual scarring of the lining of the bronchial tubes, and resultant airways narrowing. In advanced disease, the bronchi (large airways) and bronchioles (smaller airways) are infected with pus and inflammation leading to narrowing of both sets of airways. Early in the disease, the inflammation of the small airways is reversible if smoking is stopped early.

COPD is the term encompassing chronic bronchitis and emphysema. In most people, there is considerable overlap in the two conditions although each condition may exist by itself. COPD does not include other obstructive lung diseases such as asthma.