Bronchitis; Causes, Symptoms, Diagnosis, Treatment

Bronchitis is an inflammation of the lining of the bronchi of lungs. It is a very common presentation in an emergency department, urgent care center, and primary care office. About 5% of adults have an episode of acute bronchitis each year. An estimated 90% of these seek medical advice for the same. In the United States, acute bronchitis is among the top ten most common illness among outpatients. Acute bronchitis typically lasts ten to 20 days (median in a study was 18 days) but can last for more than 4 weeks.

Types of Bronchitis

Acute bronchitis

Acute bronchitis is a shorter illness that commonly follows a cold or viral infection, such as the flu. It consists of a cough with mucus, chest discomfort or soreness, fever, and, sometimes, shortness of breath. Acute bronchitis usually lasts a few days or weeks.

Chronic bronchitis

Chronic bronchitis is a serious, ongoing illness characterized by a persistent, mucus-producing cough that lasts longer than 3 months out of the year for more than 2 years. People with chronic bronchitis have varying degrees of breathing difficulties, and symptoms may get better and worse during different parts of the year.If chronic bronchitis occurs with emphysema, it may become chronic obstructive pulmonary disease (COPD).

Causes of Bronchitis

Acute bronchitis can be caused by contagious pathogens, most commonly viruses. Typical viruses include respiratory syncytial virus, rhinovirus, influenza, and others. Bacteria are uncommon pathogens but may include Mycoplasma pneumoniaeChlamydophila pneumoniaeBordetella pertussisStreptococcus pneumoniae, and Haemophilus influenzae.

  • Smoking Smoking is the leading cause of chronic bronchitis. Cigarettes are still the most commonly smoked product, but pipes and other inhalants and devices through which people smoke are also likely to cause the chronic inflammatory reaction. Each type of substance smoked, whether tobacco or any other material, causes damage to the bronchi, inflammation, mucus buildup, and obstruction.
  • Chemical inhalants – Close and frequent exposure to concentrated inhaled chemicals in the air can cause bronchitis. This is most commonly seen in the work setting. People who may be exposed to such fumes are advised to wear protective gear to minimize the dangers. Of course, financial access to such gear and verification of the quality of protective wear is easier to attain for those who have resources.
  • Pollution – Exposure to pollution, unlike exposure to inhalants in close proximity, affects people who dwell in the vicinity of high levels of pollution. This may be related to chemicals in nearby factories, automobile fumes, waste material, or other systematic issues
  • Urban environment Some studies show that people living in urban environments are more likely to be hospitalized for bronchitis. While this may be at least partially related to access to healthcare in urban settings, it appears that the urban settings themselves may put people at a higher risk of bronchitis due to inhalant exposure.
  • Damage caused by irritation of the airways leads to inflammation and leads to neutrophils infiltrating the lung tissue.
  • Mucosal hypersecretion is promoted by a substance released by neutrophils.
  • Further obstruction to the airways is caused by more goblet cells in the small airways. This is typical of chronic bronchitis.
  • Although infection is not the reason or cause of chronic bronchitis, it is seen to aid in sustaining bronchitis.

Symptoms of Bronchitis

The symptoms of both acute and chronic bronchitis include:

  • A dry cough
  • A productive cough, which brings up thick and/or discolored mucus. This mucus mixed with saliva is often referred
  • Clear, yellow, white, or green phlegm
  • No fever, although you might have a low fever at times
  • Tenderness or soreness in your chest when you a cough
  • You feel tired all the time
  • Whistling or wheezing while you breath
  • A rattling feeling in your chest to as sputum.
  • Sinus congestion
  • Chest congestion
  • Shortness of breath
  • Wheezing
  • Fatigue
  • Body aches or chills
  • Chest discomfort from coughing

Diagnosis of Bronchitis

Mild peri hilar cuffing as seen in viral bronchitis

A physical examination will often reveal a decreased intensity of breath sounds, wheezing, rhonchi, and prolonged expiration. Most physicians rely on the presence of a persistent dry or wet cough as evidence of bronchitis.

A variety of tests may be performed in patients presenting with a cough and shortness of breath

  • A chest X-ray is useful to exclude pneumonia which is more common in those with a fever, fast heart rate, fast respiratory rate, or who are old.[rx]
  • A sputum sample showing neutrophil granulocytes (inflammatory white blood cells) and culture showing that has pathogenic microorganisms such as Streptococcus species.
  • A blood test would indicate inflammation (as indicated by a raised white blood cell count and elevated C-reactive protein).
  • Pulmonary function tests
  • Arterial blood gas
  • Chest X-ray
  • Pulse oximetry (oxygen saturation testing)
  • Complete blood count (CBC)
  • Throat swab – to test for possible causes of acute bronchitis, such as influenza.
  • Chest X-ray – A chest X-ray can help determine if you have pneumonia or another condition that may explain your cough. This is especially important if you ever were or currently are a smoker.
  • Sputum tests – Sputum is the mucus that you cough up from your lungs. It can be tested to see if you have illnesses that could be helped by antibiotics. Sputum can also be tested for signs of allergies.
  • Pulmonary function test – During a pulmonary function test, you blow into a device called a spirometer, which measures how much air your lungs can hold and how quickly you can get air out of your lungs. This test checks for signs of asthma or emphysema.
  • Sputum culture –  If your symptoms are severe, your doctor might get a sample of the mucus you cough up (sputum). A lab test can tell whether the mucus is caused by an allergy or a whooping cough (pertussis), which is a very contagious bacterial infection. Serious symptoms may also mean another test.
  • Spirometry –  This is a test of your lung function. It measures how much air your lungs can hold and how quickly you can blow it all out. The test can help your doctor find out whether you have asthma or another breathing problem, along with your bronchitis.
  • High-Resolution Computed Tomography (HRCT) – This is a special type of CT scan that provides your doctor with high-resolution images of your lungs. Having an HRCT is no different than having a regular CT scan; they both are performed on an open-air table and take only a few minutes.

Treatment of Bronchitis

  • Avoid smoke and fumes – Both acute and chronic bronchitis can be exacerbated by cigarette smoke, industrial inhalants, and fumes in the environment, such as smoke from a grill. Whenever possible, stay away from inhaled irritants, as they can induce an increased inflammatory reaction of your bronchi.
  • Humidifiers – Using a humidifier may relieve discomfort when you have acute bronchitis, and sometimes this helps with chronic bronchitis as well. Humidifiers add moisture to the air, making it easier to breathe and loosening mucus. It can even relieve some of the pain that ensues from breathing dry air.
  • Rest – Acute bronchitis can cause you to feel very tired. This is due to both the infection and the persistent cough. It is important to rest as much as possible when you are sick.
  • Fluids – Drinking clear liquids when you have any type of respiratory infection is important because you need to stay hydrated, which helps thin the mucus in your chest and throat.

Over-the-Counter Therapies

A number of over-the-counter medications can help relieve some of the symptoms of both acute and chronic bronchitis. In general, these medications are more effective for short-term use if you have acute bronchitis. Most of the time, your doctor will recommend prescription-strength medication that has a more lasting effect for chronic bronchitis.

  • Decongestants  – Decongestants such as Sudafed (pseudoephedrine) and Afrin (oxymetazoline) loosen and help drain the mucus that may be in your sinuses, making it easier for you to breathe. There is some controversy about abuse of these medications, so it is important to be responsible and use them conservatively. Use decongestants only if they relieve your symptoms, and for no longer than a few days at a time.
  • Pain relievers – Pain relievers and fever reducers such as acetaminophen and ibuprofen can help relieve the chest pain and soreness that you may experience from coughing when you have bronchitis.
  • Fever reducers – Many of the medications that can reduce your fever also relieve mild pain, so these over-the-counter medications can do double duty. Do not take them in doses higher than recommended, and be sure to tell your doctor or your child’s pediatrician about over-the-counter medications that you are using.
  • Cough medications – Cough suppressants or expectorants may be helpful if your cough is dry or unproductive. If you have a persistent cough with chronic bronchitis, your doctor may give you a prescription cough suppressant.  although coughing should not be completely suppressed as this is an important way to bring up mucus and remove irritants from the lungs. If you want to buy cough medicine, then there is an excellent selection online with thousands of customer reviews.
  • Mucolytics – these thin or loosen mucus in the airways, making it easier to cough up sputum.
  • Anti-inflammatory medicines and glucocorticoid steroids – these are for more persistent symptoms to help decrease chronic inflammation that may cause tissue damage.
  • Oxygen therapy – this helps improve oxygen intake when breathing is difficult.
  • Pulmonary rehabilitation program – this includes work with a respiratory therapist to help improve breathing.

Prescription treatments for bronchitis are given for comfort, and some prescription treatments can help the disease itself to get better.

  • Antibiotics – Most cases of acute bronchitis are caused by viral infections, which means that they cannot be treated with antibiotics. Amoxicillin, doxycycline, erythromycin, and trimethoprim-sulfamethoxazole seem reasonable first choices. The evidence for bronchodilators is conflicting. A review by Williamson claims that randomized clinical trials support the use of bronchodilators; however, a review by Smucny et al states that there is no consistent benefit. Taking them will not help you get better any faster and can lead to other problems, such as antibiotic resistance. If you have acute bronchitis caused by a bacterial infection, you may need to take prescription antibiotics. The specific antibiotic is determined based on the likely bacterial organism. If you do need to take antibiotics, be sure to take all of your medication as prescribed and do not stop just because you are feeling better.
  • Bronchodilators – Short and long-acting β-Adrenergic receptor Agonists as well as Anticholinergic help by increasing the airway lumen, increasing ciliary function and by increasing mucous hydration.
  • Glucocorticoids – Reduce inflammation and mucus production. Inhaled corticosteroids reduce exacerbation and improve quality of life. However, it is administered under medical supervision and for short periods of time as long-term usage can induce osteoporosis, diabetes, and hypertension.
  • Phosphodiesterase-4 inhibitors – decrease inflammation and promote airway smooth muscle relaxation by preventing the hydrolysis of cyclic adenosine monophosphate a substance when degraded leads to the release of inflammatory mediators.
  • Bronchodilators – Bronchodilators such as Proventil (albuterol) relax the muscles around the bronchi, allowing them to become wider. This helps remove bronchial secretions while relieving bronchospasm and reducing airway obstruction. Your wheezing and chest tightness may temporarily improve, and more oxygen can be distributed to your lungs to improve your energy level. Some of these medications are referred to as rescue inhalers because they work quickly and are used to treat sudden episodes of shortness of breath related to bronchospasm.
  • Steroids – Oral steroids may be used to treat chronic bronchitis when symptoms rapidly get worse. Inhaled steroids are typically used to treat stable symptoms or when symptoms are slowly getting worse.
  • Phosphodiesterase-4 (PDE4) Inhibitors – PDE4 inhibitors Daliresp (roflumilast) are a class of medication that treats inflammation associated with lung disease. A once-daily oral medication, PDE4 inhibitors help reduce exacerbation of chronic bronchitis, typically with minimal side effects.
  • Vaccines — Patients with chronic bronchitis should receive a flu shot annually and pneumonia shot every five to seven years to prevent infections.
  • Oxygen Therapy — As a patient’s disease progresses, they may find it increasingly difficult to breathe on their own and may require supplemental oxygen. Oxygen comes in various forms and may be delivered with different devices, including those you can use at home.
  • Pulmonary Rehabilitation — An important part of chronic bronchitis treatment is pulmonary rehabilitation, which includes education, nutrition counseling, learning special breathing techniques, help with quitting smoking and starting an exercise regimen. Because people with chronic bronchitis are often physically limited, they may avoid any kind of physical activity. However, regular physical activity can actually improve a patient’s health and wellbeing.
  • Robitussin and Delsym – Use this medicine sparingly because coughing helps remove irritants from the air passages, and you want to cough these irritants out of these passges in the lungs.
  • Surgery — Lung volume reduction surgery, during which small wedges of damaged lung tissue are removed, may be recommended for some patients with chronic bronchitis.

[dropshadowbox align=”none” effect=”lifted-both” width=”auto” height=”” background_color=”#ffffff” border_width=”2″ border_color=”#dddddd” ]


Intervention Mechanism of Action
  • Smoking cessation
Improves mucociliary function, decreases goblet cell hyperplasia
  • Physical measures (chest PT, HFCWO, flutter valve)
Augments shear stresses to improve mucociliary clearance
  • Expectorants
Vagally mediated increase in airway secretions
  • Mucolytics (hypertonic saline,dornase alpha)
Rehydration of airway mucus, hydrolysis of mucus DNA
  • Methylxanthines
Improves lung function, increases ciliary beat frequency
  • SABA
Improves lung function, increases ciliary beat frequency
  • LABA
Improves lung function, increases ciliary beat frequency, reduces hyperinflation, improves PEF
  • Anticholinergics
Improves lung function, decreases mucus secretion
  • Glucocorticoids
Reduces inflammation and mucus production
  • PDE-4 inhibitors
Reduces inflammation, improves lung function
  • Antioxidants
Breaks down mucin polymers, reduces mucus production
  • Macrolides
Reduces inflammation, reduces goblet cell secretion

Definition of abbreviations: HFCWO = high-frequency chest wall oscillation; LABA = long-acting β-adrenergic receptor agonist; PDE-4 = phosphodiesterase-4; PEF = peak expiratory flow; PT = physiotherapy; SABA = short-acting β-adrenergic receptor agonist.


Smoking Cessation

  • Smoking cessation can improve a cough in many patients with CB by improving mucociliary function and by decreasing goblet cell hyperplasia (). Smoking cessation has also been shown to decrease airway injury and lower levels of mucus in exfoliated sputum tracheobronchial cells compared with those who continued to smoke (). A large longitudinal follow-up study found that the incidence rates of CB were much higher in current smokers compared with ex-smokers (42 vs. 26%) ().

Physical Measures

  • Mucus clearance is aided by maneuvers that promote coughing and increase minute ventilation, including exercise. This augments shear stresses on mucosal surfaces generated by increased airflow. It also increases humidification of the airway and regulates mucus hydration.
  • Thus, methods such as the application of positive expiratory pressure or use of flutter valves or high-frequency chest compression vests may be of value but have not been studied for use in COPD in large clinical trials.
  • Although cystic fibrosis studies have demonstrated that chest percussion and postural drainage improve mucociliary clearance, these methods have not been well studied in the COPD patient population.
  • Few studies have addressed chest physiotherapy or directed coughing techniques in COPD, which have shown some improvements in mucus clearance but no changes in lung function ().

Expectorants and Mucolytics

  • Guaifenesin works by promoting vagally mediated increase in airway secretions (). Although it has been shown to help with the common cold, long-term use of guaifenesin has not been shown to be of benefit in COPD or CB (). Inhaled hypertonic saline works not only by rehydrating mucus by drawing water from epithelial cells but also by promoting cough ().
  • Although this method has been proved to improve lung function in cystic fibrosis, it has only been shown in one study in COPD to improve dyspnea and exercise capacity (). Inhaled dornase alfa hydrolyzes DNA, thereby improving lung function and decreasing exacerbation frequency in patients with cystic fibrosis, in whom airway mucus concentrations of DNA are high. However, the concentration of DNA in patients with COPD is much lower (), and dornase alfa not only is not beneficial but it may also be harmful ().

Methylxanthines and Short-Acting β-Adrenergic Receptor Agonists

Both methylxanthines and short-acting β-adrenergic receptor agonists (SABAs) promote mucus clearance by several mechanisms:

  • Increase airway luminal diameter;
  • Increase ciliary beat frequency via an increase in intracellular cyclic adenosine monophosphate levels; and
  • Increase mucus hydration by stimulating airway Cl secretion via activation of the cystic fibrosis transmembrane regulator.
  • This decreases mucus viscosity, allowing for easier transport by airway cilia (). In animal models, short-term administration of β-agonists is associated with up-regulation of mucociliary clearance.
  • Similarly, methylxanthines improve mucociliary clearance not only via their bronchodilatory properties but also by stimulating ciliary beat frequency, augmenting airway epithelial ion transport to increase mucus hydration and promoting mucus secretion in the lower airways (). Clinical studies of theophylline in CB have shown improved lung function but no consistent change in cough and sputum production ().

Long-Acting β-Adrenergic Receptor Agonists

  • The effects of long-acting β-adrenergic receptor agonists (LABAs) on mucociliary function have been attributed to their beneficial effects on lung function (). LABAs also reduce hyperinflation and increase peak expiratory flow, which are essential components of effective cough ().
  • In vitro evidence has shown that salmeterol can stimulate ciliary beat frequency. Similarly, formoterol significantly improves mucociliary clearance compared with placebo in patients with bronchitis ().


  • Anticholinergics, by their action on the muscarinic receptor, are believed to help mucus clearance by increasing luminal diameter and by decreasing surface and submucosal gland mucin secretion (). They are also believed to facilitate cough-induced mucus clearance. However, anticholinergics may desiccate airway secretions by depleting airway surface liquid, thereby making secretions more difficult to expectorate.
  • In vivo, the literature does not support the use of anticholinergics for the treatment of CB. Ipratropium bromide has been shown to reduce the quantity and severity of coughs in chronic bronchitis () but is not effective in improving mucociliary clearance in COPD ().
  • In a study of 470 patients with FEV1, 39% predicted, tiotropium improved lung function but did not affect cough symptoms (). In another study of 39 patients with COPD, tiotropium reduced the number of coughs, but mucociliary clearance was not improved ().


  • There is in vitro evidence that glucocorticoids reduce inflammation and mucus production (). In a murine model of asthma, inhaled corticosteroids decrease goblet cell hyperplasia (). Dexamethasone has also been shown to decrease epithelial mucin gene MUC5AC gene expression in human bronchial epithelial cells ().
  • They may also hasten mucociliary clearance (). Inhaled corticosteroids reduce exacerbation frequency and improve quality-of-life scores in COPD (). Whether inhaled corticosteroids are more beneficial in patients with COPD with CB or airway-predominant phenotypes remains to be determined.

Phosphodiesterase-4 Inhibitors

  • Phosphodiesterase-4 (PDE-4) inhibition decreases inflammation and promotes airway smooth-muscle relaxation by preventing the hydrolysis of cyclic adenosine monophosphate to its inactive metabolite. Cilomilast and roflumilast are highly specific second-generation oral PDE-4 inhibitors.
  • The overwhelming majority of patients (78–100%) in these trials had chronic cough and sputum production at enrollment. In both trials, roflumilast significantly improved the primary endpoint, pre-bronchodilator FEV1, as well as the exacerbation rate. Thus, as CB increases risk for exacerbation, PDE-4 inhibitors may play a preferential role in preventing the development of exacerbation in patients with CB and COPD.


  • As oxidative stress is crucial to the pathogenesis of COPD (), antioxidant therapy may be of benefit in COPD treatment. Thiol compounds are powerful antioxidants and include N-acetylcysteine, N-acystelyn, carbocysteine, erdosteine, and fudosteine.
  • The two most extensively studied antioxidant medications for COPD are N-acetylcysteine and carbocysteine. N-Acetylcysteine is a precursor of l-cysteine and reduced glutathione, which reduces cellular levels of oxidative stress and production of reactive oxygen species.
  • N-Acetylcysteine also reduces disulfide bonds and sulfhydryl bonds that link together mucin polymers, thereby reducing sputum viscosity. Carbocysteine is a blocked thiol derivative of l-cysteine with in vitrofree-radical scavenging and antiinflammatory properties and may work on the fucose and sialic acid content in mucus ().

Specialist-Driven Procedures

  • Several procedures can help relieve the symptoms and congestion of chronic bronchitis. These procedures are primarily non-invasive and easy to tolerate but must be directed by an experienced specialist.
  • Chest physiotherapy – This procedure, which may also be referred to as chest percussion, is a technique which involves clapping on the chest and/or back to help loosen mucus and make it easier to cough up. It is often used with postural drainage and can be performed using cupped hands or an airway clearance device.
  • Postural drainage –This technique uses gravity to assist with the removal of mucus from the airways. Both chest physiotherapy and postural drainage work best after a bronchodilator treatment.
  • Airway clearance devices – These devices are used in conjunction with chest therapy and postural drainage to better ensure mucus clearance from the lungs. The devices have been shown to improve results compared to physiotherapy and drainage alone. They are relatively affordable and easy to use, and your therapist or doctor may recommend a device if you have chronic bronchitis.
    • Positive expiratory pressure (PEP) devices allow you to breathe against air pressure.
    • High-frequency oscillating devices, such as the Flutter mucus clearance device and the Acapella vibratory PEP device, gently allow the small and large airways to vibrate.
    • The Lung Flute, a hand-held device, generates low-frequency sound waves into the airways.

1 comment

Leave a comment

Your email address will not be published. Required fields are marked *