Acute Bronchitis

Introduction

Acute bronchitis is a temporary inflammation of the bronchial tubes, the airways that carry air to the lungs. It is typically caused by viral infections, such as the common cold or flu, and often follows an upper respiratory infection.

Symptoms include a persistent cough, chest discomfort, mucus production, and sometimes mild fever or fatigue. While it usually resolves within a few weeks without specific treatment, supportive care like rest, hydration, and over-the-counter medications can help manage symptoms.

Types of Bronchitis 

• Acute bronchitis: It typically results from a viral infection and resolves on its own within a few weeks. The majority of people with acute bronchitis do not require treatment.
• Chronic bronchitis: You have chronic bronchitis if you have a cough that usually produces mucus for three months of the year. This continues for a minimum of two years.

Acute Bronchitis: What is it?

Inflammation of the bronchi (large and medium-sized airways) of the lungs is the short-term form of acute bronchitis, commonly referred to as a chest cold.

Coughing is the most prevalent symptom. Coughing up mucous, wheezing, dyspnea, fever, and chest pain are further symptoms. The duration of the infection could range from a few to ten days.

The length of symptoms typically lasts three weeks, but the cough may continue for a few weeks after that. For up to six weeks, some people may have symptoms.

A viral infection is the cause of 90% of cases. These viruses can be transferred by direct touch or through coughing. Exposure to dust, tobacco smoke, and other air pollutants are risk factors.

A tiny percentage of cases are caused by bacteria like Bordetella pertussis or Mycoplasma pneumoniae, or by high levels of air pollution. Usually, a person’s symptoms and signs are used to make the diagnosis.

The color of the sputum does not indicate if the illness is viral or bacterial. Generally, there is no requirement to identify the underlying organism. Similar symptoms can also be caused by COPD, bronchiolitis, pneumonia, asthma, and bronchiectasis. An X-ray of the chest could help identify pneumonia.

Acute bronchitis is typically treated with rest, paracetamol (acetaminophen), and NSAIDs to reduce fever; cough medicine has little evidence to support its use and is not advised for children younger than six. Antibiotics should generally be avoided except in cases where pertussis is the cause of acute bronchitis.

Prevention is achieved by staying away from smoking and other lung irritants; frequent hand washing and vaccination may also be protective; there is some evidence to support the use of honey and pelargonium as symptom treatments.

Epidemiology

Acute bronchitis is one of the most prevalent illnesses, affecting approximately 5% of adults and 6% of children, with a higher incidence during the winter months.

Over 10 million Americans seek medical attention for acute bronchitis each year, and 70% of them receive antibiotics, the majority of which are unnecessary. Efforts are being made to reduce the use of antibiotics for acute bronchitis.

Acute bronchitis can also be caused by a number of risk factors, such as a history of asthma, living in a crowded environment, living in a polluted location, and smoking. For those who are vulnerable, some allergens like pollen, perfume, and fumes may cause acute bronchitis.

When the infection is bacterial in origin, the isolated pathogens often overlap with those associated with community-acquired pneumonia. These bacteria include Streptococcus pneumonia and Staphylococcus aureus.

Pathophysiology

Acute bronchitis, which is often caused by viral infections, is an inflammation of the large and mid-sized airways (bronchi). The various effects of these microorganisms on the respiratory tract are highlighted by the large number of anatomical locations within the respiratory tract where these pathogens can establish themselves.

When viewed by positron-emission tomography (PET) scan, the inflammatory process causes elevated 18F-fluorodeoxyglucose (FDG) uptake due to increased blood flow and cellular activity within the affected bronchi.

Furthermore, a number of factors can cause bronchial inflammation, although the most frequent ones include viruses, allergies, and pollution. Mucosal thickening, desquamation of epithelial cells, and basement membrane degradation are the results of bronchial wall inflammation.

Acute bronchitis can occasionally develop from a viral upper respiratory illness that progresses to a lower respiratory tract infection.

Acute bronchitis in children

The risk of acute bronchitis is higher in children than in adults. This is partially caused by risk factors that are specific to individuals and could include:

• Elevated viral exposure in places like playgrounds and schools
• Asthma allergies
• Chronic sinusitis
• Enlarged tonsils
• Inhaled particles, including dust

Cause

Most often, viruses, infectious organisms can cause acute bronchitis. Typical viruses include influenza, rhinovirus, respiratory syncytial virus, and others.

Despite being rare pathogens, bacteria can include Haemophilus influenzae, Bordetella pertussis, Streptococcus pneumoniae, Mycoplasma pneumoniae, and Chlamydophila pneumoniae.

Damage from irritated airways leads to inflammation and the entry of neutrophils into the lung tissue.

Mucosal hypersecretion is encouraged by a chemical produced by neutrophils.

More goblet cells in the small airways cause further obstruction of the airways.

Although infection is neither the cause nor the source of chronic bronchitis, it is thought to be related to its support.

Symptoms

Acute bronchitis first presents with symptoms that resemble those of the flu or a cold.

These signs may consist of:

• Fatigue,
• Sore throat, and runny nose
• Sneezing,
• Wheezing,
• Back and muscle pain,
• Feeling chilly easily, and
• Having a temperature between 100°F and 100.4°F (37.7°C and 38°C)
• Unexpected weight loss, loud cough, and breathing difficulties
• Chest pain

After the initial infection, you will probably have a cough. Frequently, a dry cough will develop into a productive one that produces mucus. The most typical sign of acute bronchitis is a productive cough, which may persist anywhere from 10 days to 3 weeks.

A change in mucus color from white to green or yellow is another symptom you could observe. This does not mean that you have a bacterial or viral infection. It just indicates that your immune system is functioning.

Risk factors

The following variables raise your risk of developing acute bronchitis:

• Inhaling secondhand smoke and cigarette smoke
• Weak immune system or poor tolerance to diseases, gastric reflux
• Regular contact with irritants, such as dust or chemical fumes
• Absence of whooping cough, pneumonia, and flu vaccinations among those over 50

Complications

Complications associated with acute bronchitis include:

• Secondary pneumonia
• Acute respiratory distress syndrome
• Prolonged symptoms
• Spontaneous pneumothorax
• Spontaneous pneumomediastinum

Prevention

By making every effort to maintain your health and the health of others, you can help prevent acute bronchitis. This includes:

• Wash your hands.
• Obtain recommended vaccinations, like the flu vaccine.
• Avoid secondhand smoke and avoid from smoking.
• When you cough or sneeze, keep your mouth and nose covered.

Prognosis

Acute bronchitis typically resolves on its own with symptomatic treatment. Clinicians should, however, continue to be mindful of possible secondary problems, like pneumonia. The medical staff should, therefore, be aware of potential side effects and be ready to administer the appropriate treatments if necessary, even though symptomatic treatment for acute bronchitis is often effective.

Diagnosis

Viral bronchitis is characterized by mild peri-bronchial cuffing.

During a physical examination, wheezing, rhonchi, extended expiration, and diminished breath sound intensity are frequently observed. Physicians base their evaluation on the patient’s history and whether they have a persistent or sudden onset cough, a URTI, and no signs of pneumonia.
Patients with an acute onset cough, which frequently occurs after a URTI without signs of pneumonia, should be suspected of having acute bronchitis, which is usually a clinical diagnosis based on the patient’s history and examination.

A set of useful criteria has been offered for acute bronchitis despite the lack of a widely recognized clinical definition. These criteria include:

• Fewer than three weeks of acute sickness.
• Coughing is the most common symptom.
• At least one additional lower respiratory tract symptom, like chest pain, wheezing, or sputum production.

People who present with coughing and dyspnea may undergo a number of tests:

To rule out pneumonia, which is more likely in those who have a fever, a fast heartbeat, a fast breathing rate, or are elderly, a chest X-ray is helpful.

A culture containing pathogenic microorganisms like Streptococcus species and a sputum sample containing neutrophil granulocytes (inflammatory white blood cells) are both present.

An elevated white blood cell count and elevated C-reactive protein would be signs of inflammation in a blood test.

The chest may produce crackles, wheezing, rhonchi that clear with coughs, and a decrease in breath sounds. Pleural rub and dullness to percussion indicate that the illness has spread outside the bronchi, as in the case of pneumonia. Pertussis is suggested by coughing fits that are followed by vomiting and inspiratory whooping.

Differential Diagnosis

It is important to take into account additional possible causes of acute cough, particularly if it lasts longer than three weeks. The following are additional factors to take into account:

• Asthma: Since about one-third of patients present with an acute cough, acute asthma worsening symptoms are commonly incorrectly diagnosed as acute bronchitis.
• Acute or chronic sinusitis
• Bronchiolitis
• COPD
• Gastroesophageal reflux disease (GERD)
• Viral pharyngitis
• Heart failure
• Pulmonary embolism
• Pneumonia

Treatment

The majority of cases resolve on their own within a few weeks. Medication for pain can help with symptoms. Additional advice might include getting enough sleep and drinking plenty of water.

Antibiotics

The widespread use of antibiotics for acute bronchitis is not supported by evidence. Antibiotics decreased cough by an average of 12 hours, out of a total average of roughly 14–28 days, according to a systematic review. In addition to causing more adverse effects like nausea and diarrhea, antibiotics may also encourage bacteria that are resistant to them. They might be helpful in vulnerable populations, like the elderly and the weak.

Decrease smoking

Alternative methods of treatment

Children without restricted airways who have an acute cough do not respond well to salbutamol. Although there is little proof that salbutamol helps adults who are wheezing because of a narrowed airway, it can cause tremor, shakiness, or anxiety.

Physical Therapy

The physical therapist’s objectives should include education, enhancing exercise tolerance, decreasing hospitalization and exacerbations, helping to clear sputum, and increasing lung volume and thoracic mobility.

Treatment for acute bronchitis should include both respiratory physical therapy and pulmonary rehabilitation.

Education

Morbidity and quality of life are significantly impacted by chronic bronchitis. The psychological effects of having a chronic condition may be decreased and an active approach to management may be encouraged if the treating clinical staff educates the person with acute bronchitis about the presenting condition, medication use, treatment options, and self-management.

Quitting smoking is the most important nonpharmacological intervention. It reduces goblet cell hyperplasia and enhances mucociliary function. It has also been demonstrated that quitting smoking lessens airway damage, lowering the amount of mucus removed from tracheobronchial cells.

Exercise

Acute bronchitis and COPD can be effectively managed, treated, and prevented with regular exercise.

Reduced airflow obstruction, airway clearance, enhanced functional abilities, elevated energy levels, and sputum expectoration have all been demonstrated to improve with aerobic exercise and upper and lower limb resistance training.

Before beginning any exercise program, a consultation with the general practitioner should be held, and the treating clinical team (such as a physiotherapist) should oversee the program.

Physical Fitness

Upper and lower limb resistance training and aerobic exercise can improve energy levels, functional tolerance, and physical fitness while reducing hospitalizations, exacerbations, and shortness of breath.

Particular advice are made regarding exercise for people with COPD and chronic bronchitis. Before beginning any exercise program, a discussion with the treating clinical team should be held.

Secretion clearance:

• Active Cycle of Breathing
• Autogenic Drainage
• Positive Expiratory Pressure (PEP)
• Oscillating positive expiratory pressure
• Effective / productive coughing techniques.
• Postural drainage in sitting and lying.
• Manual techniques, including percussion and vibrations

Breathing techniques:

• Controlling respiratory rate
• Diaphragmatic breathing
• Relaxation breathing exercises

FAQs

References

• Singh, A., Avula, A., & Zahn, E. (2024, March 9). Acute bronchitis. StatPearls – NCBI Bookshelf. https://www.ncbi.nlm.nih.gov/books/NBK448067/
• Acute bronchitis. (2024, October 10). Johns Hopkins Medicine. https://www.hopkinsmedicine.org/health/conditions-and-diseases/acute-bronchitis#:
• Bronchitis. (2025b, January 6). Cleveland Clinic. https://my.clevelandclinic.org/health/diseases/3993-bronchitis