Excess mucus can narrow the airways, thereby limiting airflow and accelerating the decline in lung function, and result in COPD. Excess mucus shows itself as a chronic productive cough and its severity and volume of sputum can fluctuate in periods of acute exacerbations. In COPD, those with the chronic bronchitic phenotype with associated chronic excess mucus, experience a worse quality of life than those without.The increased secretions are initially cleared by coughing. The cough is often worse soon after awakening, and the sputum produced may have a yellow or green color and may be streaked with specks of blood. In the early stages, a cough can maintain mucus clearance. However, with continued excessive secretion mucus clearance is impaired, and when the airways become obstructed a cough becomes ineffective. Effective mucociliary clearance depends on airway hydration, ciliary beating, and the rates of mucin secretion. Each of these factors is impaired in chronic bronchitis. Chronic bronchitis can lead to a higher number of exacerbations and a faster decline in lung function. The ICD-11 lists chronic bronchitis with emphysema (emphysematous bronchitis) as a "certain specified COPD". Cause
Most cases of chronic bronchitis are caused by tobacco smoking. Chronic bronchitis in young adults who smoke is associated with a greater chance of developing COPD. There is an association between smoking cannabis and chronic bronchitis.
History
The condition of bronchitis has been recognised for many centuries, in several different cultures including the Ancient Greek, Chinese, and Indian, with the presence of excess phlegm and cough noted in recognition of the same condition. Early treatments of chronic bronchitis included garlic, cinnamon and ipecac, among others. Modern treatments were developed during the second half of the 20th century.In Britain in 1808, a physician Charles Badham was the first person to describe the condition and name the acute form as acute bronchitis. This was written of in a book entitled Inflammatory conditions of the bronchia. In this book Badham distinguished three forms of bronchitis including acute and chronic. A second edition of this book was renamed An Essay on Bronchitis and published in 1814. Bradham used the term catarrh to refer to the cardinal symptoms of chronic cough and mucus hypersecretion of chronic bronchitis, and described chronic bronchitis as a disabling disorder.In 1901 an article was published on the treatment of chronic bronchitis in the elderly. The symptoms described have remained unchanged. The cause was thought to be brought on by dampness, cold weather, and foggy conditions, and treatments were aimed towards various cough mixtures, respiratory stimulants, and tonics. It was noted that something other than the weather was thought to be at play. Exacerbations of the condition were also described at this time. Another physician Harry Campbell was referred to who had written in the British Medical Journal a week before.