Acute Bronchitis

Acute bronchitis is a lower respiratory tract infection in which the bronchial tubes, the larger airway of the lungs, become inflamed and filled with mucus. Viral infections account for the majority of acute bronchitis cases, whereas bacterial infections are uncommon. Upper respiratory tract infections, like the common cold, can sometimes lead to acute bronchitis.^[1][2]

Coughing, with or without mucus, is the predominant symptom of acute bronchitis. The cough usually lasts 10–20 days but may last up to 4 weeks, even after resolution of the primary infection itself. Chest discomfort, nasal congestion, mild shortness of breath, malaise, headache, and fatigue are other common symptoms.^[2]

A healthcare professional makes the diagnosis of acute bronchitis based on a history and physical exam, which may include listening to the lungs with a stethoscope and measuring oxygen levels with a sensor placed on a finger. During this assessment, other possible conditions (e.g., pneumonia or COPD) should be ruled out. Chest x-rays and microbiological testing are not necessary to make the diagnosis of acute bronchitis, although they may be used if abnormal vital signs are present (such as increased heart rate, breathing, and fever), if there are signs of fluid in the lungs, and in at-risk populations (e.g., the elderly and immunocompromised.^[3]

Acute bronchitis usually resolves on its own. Simple interventions, like getting enough rest, consuming honey (if over the age of one), and using saline nasal sprays, cough drops, and/or a humidifier, can relieve some discomfort. However, medications to treat symptoms may be prescribed.

Coughing is often treated with antitussive medications (cough suppressants) such as dextromethorphan; however, some research suggests that it may be less effective than honey at relieving coughing.^[4] Some small studies have found that albuterol inhalers may be helpful for treating cough,^[5][6] but clinical guidelines only recommended their use in people with a history of wheezing or bronchial obstruction.^[7][3] For pain and fever, acetaminophen or nonsteroidal anti-inflammatory drugs (e.g., ibuprofen) may be used. Lastly, expectorants (drugs that thin and loosen mucus) such as guaifenesin can help clear mucus from the lungs. Antibiotics are not recommended for acute bronchitis, since most cases are caused by a virus,^[8] and the risks and costs of these medications usually outweigh any of the minor benefits they provide.^[9]

It is important to note that medical treatments differ across populations and may change depending on a person’s age and/or co-occurring conditions. For example, antihistamine and antitussive medications are not indicated for use in children under the age of four.^[3]

There is inadequate evidence from randomized controlled trials to support the efficacy of medicinal herbs used in traditional Chinese medicine to treat acute bronchitis.^[10] However, the supplement Umckaloabo may assist in easing the symptoms of acute bronchitis.^[11]

There is little research on diet and acute bronchitis. Some research has found that fruit and vegetable intake is associated with a decreased risk of chronic obstructive pulmonary disease (COPD)^[12], but it is unclear whether the same benefit applies to acute bronchitis.

Fluid intake is another important dietary consideration. Although increasing fluid consumption is frequently advised when recovering from acute bronchitis, there is no evidence from randomized controlled studies that doing so is beneficial.^[13]

Hot tea, honey, saline nasal sprays, humidifiers, steam inhalation, and throat lozenges are commonly used to alleviate the symptoms of acute bronchitis, including cough and sore throat. Although there is little evidence of their efficacy in randomized controlled trials, these remedies are generally safe and may be beneficial for some people.

Viruses (e.g., respiratory syncytial virus (RSV), enterovirus, influenza A and B, parainfluenza, coronavirus, and rhinovirus) cause approximately 90% of acute bronchitis cases. Bacterial infections are relatively uncommon, accounting for only 1%–10% of cases.^[8][3]