[6] Treatment of acute bronchitis typically involves rest, paracetamol (acetaminophen), and nonsteroidal anti-inflammatory drugs (NSAIDs) to help with the fever.

[11] Tobacco smoking is the most common cause, with a number of other factors such as air pollution and genetics playing a smaller role.

[21] Treatment for acute bronchitis usually involves rest, paracetamol (acetaminophen), and NSAIDs to help with the fever.

[2] More than 10 million people in the U.S. visit a healthcare provider each year for this condition, with about 70% receiving antibiotics that are mostly unnecessary.

[34] A Chinese consensus commented on symptomatic types of COPD that include chronic bronchitis with frequent exacerbations.

[9][36] The excess mucus is produced by an increased number of goblet cells, and enlarged submucosal glands in response to long-term irritation.

[38] Mucins thicken mucus, and their concentration has been found to be high in cases of chronic bronchitis, and also to correlate with the severity of the disease.

[39] Excess mucus can narrow the airways, thereby limiting airflow and accelerating the decline in lung function, and result in COPD.

[35][40] Excess mucus shows itself as a chronic productive cough and its severity and volume of sputum can fluctuate in periods of acute exacerbations.

[36] 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.

However, with continued excessive secretion mucus clearance is impaired, and when the airways become obstructed a cough becomes ineffective.

[43] Effective mucociliary clearance depends on airway hydration, ciliary beating, and the rates of mucin secretion.

[44] Chronic bronchitis can lead to a higher number of exacerbations and a faster decline in lung function.

[51][52] In addition, chronic inhalation of air pollution, or irritating fumes or dust from hazardous exposures in occupations such as coal mining, grain handling, textile manufacturing, livestock farming,[53] and metal moulding may also be a risk factor for the development of chronic bronchitis.

[59] Air pollution in the workplace is the cause of several non-communicable diseases (NCDs) including chronic bronchitis.

[45] A Cochrane review found that mucolytics in chronic bronchitis may slightly decrease the chance of developing an exacerbation.

Erdosteine has been shown to significantly reduce the risk of exacerbations, shorten their duration, and hospital stays.

[67] Individuals over 45 years of age, smokers, those that live or work in areas with high air pollution, and anybody with asthma all have a higher risk of developing chronic bronchitis.

[68] This wide range is due to the different definitions of chronic bronchitis that can be diagnosed based on signs and symptoms or the clinical diagnosis of the disorder.

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.

Campbell had suggested that the cause of chronic bronchitis was due to toxic substances, and recommended pure air, simple food, and exercise to remove them from the body.

[72] A joint research programme was undertaken in Chicago and London from 1951 to 1953 in which the clinical features of one thousand cases of chronic bronchitis were detailed.

The study had looked at various associations such as the weather, conditions at home, and at work, age of onset, childhood illnesses, smoking habits, and breathlessness.

[73] In 1957 it was noted that at the time there were many investigations being carried out into chronic bronchitis and emphysema in general, and among industrial workers exposed to dust.

[74] Excerpts were published dating from 1864 in which Charles Parsons had noted the occurring consequence of the development of emphysema from bronchitis.

[76] Protracted bacterial bronchitis in children, is defined as a chronic productive cough with a positive bronchoalveolar lavage that resolves with antibiotics.

[77][78] Protracted bacterial bronchitis is usually caused by Streptococcus pneumoniae, non-typable Haemophilus influenzae, or Moraxella catarrhalis.

[81] When these casts are coughed up, they are firmer in texture from typical phlegm or the short, softer mucus plugs seen in some people with asthma.

[83] Depending on the size of the casts, and the location the condition may present with mild symptoms, or prove fatal.

[84][85] In immunocompetent individuals, Aspergillus bronchitis may manifest as persistent respiratory infections or symptoms that do not respond to antibiotics, but may improve with antifungals.