Bronchitis — Acute & Chronic Types, Causes & Treatment Guide — Symptoms, Causes & Treatment | MyMedicPlus

Bronchitis is inflammation of the bronchi (air passages leading to the lungs), causing productive cough, mucus production, wheezing, and breathing discomfort. Acute bronchitis is a self-limiting viral infection lasting 1-3 weeks; chronic bronchitis is defined as productive cough on most days for at least 3 months per year for 2 consecutive years, caused predominantly by smoking. Chronic bronchitis is one of the two main conditions in COPD (chronic obstructive pulmonary disease). Acute bronchitis accounts for over 100 million GP consultations annually worldwide. Acute bronchitis is one of the most common reasons for antibiotic prescriptions — despite the fact that antibiotics are rarely indicated. This prescribing pattern contributes significantly to antibiotic resistance, making educating patients about the self-limiting viral nature of acute bronchitis a critical public health priority. Chronic bronchitis as part of COPD causes progressive airflow limitation and is associated with significant cardiovascular and metabolic comorbidities. Women with COPD tend to have more severe symptoms than men at equivalent levels of lung function.

Acute bronchitis: 90% of cases are caused by viral respiratory infections (rhinovirus, influenza A/B, parainfluenza, RSV, coronavirus, adenovirus). Bacterial causes (Bordetella pertussis, Mycoplasma pneumoniae, Chlamydophila) account for under 10% of cases. Chronic bronchitis: cigarette smoking is the primary cause — responsible for 85-90% of cases. Other risk factors include air pollution (indoor cooking fires, biomass fuels), occupational dusts and chemical fumes, passive smoking, recurrent respiratory infections, and genetic factors (alpha-1-antitrypsin deficiency). COPD exacerbations — episodes of acute worsening of symptoms in patients with established chronic bronchitis — are commonly triggered by Haemophilus influenzae, Streptococcus pneumoniae, and Moraxella catarrhalis bacterial infections, as well as by viral infections and environmental exposures. Recurrent childhood respiratory infections and uncontrolled asthma increase adult COPD risk. Outdoor air pollution (PM2.5, ozone, nitrogen dioxide) contributes to up to 14% of chronic obstructive pulmonary disease cases globally — particularly in urban and industrial areas.

Acute bronchitis: productive cough (clear, white, yellow, or green mucus), low-grade fever, sore throat, mild chest discomfort, fatigue, and sometimes wheezing. Symptoms peak around day 3-4 and resolve within 7-21 days, though cough may persist up to 8 weeks (post-infectious cough). Chronic bronchitis: persistent productive cough worse in the mornings, excessive mucus, frequent respiratory infections, progressive breathlessness on exertion, and wheezing. Cyanosis (blue-tinged lips/fingernails) in severe disease. Cor pulmonale (right heart failure from pulmonary hypertension) in advanced stages. Haemoptysis (coughing blood) is not typical of uncomplicated bronchitis and should prompt urgent investigation for lung cancer, tuberculosis, pulmonary embolism, or bronchiectasis — all serious conditions that can present with blood-tinged sputum. Any haemoptysis in a current or ex-smoker over 40 warrants urgent chest imaging. Ankle oedema in chronic bronchitis suggests cor pulmonale — right heart failure from pulmonary hypertension — indicating advanced COPD.

Acute bronchitis is a clinical diagnosis — a productive cough without pneumonia features (high fever, crackles on auscultation, consolidation on chest X-ray). Chest X-ray is not routinely required for uncomplicated acute bronchitis but excludes pneumonia in high-risk patients. Spirometry is essential for chronic bronchitis/COPD diagnosis — FEV1/FVC ratio below 0.7 post-bronchodilator confirms airflow obstruction. GOLD staging (1-4) grades COPD severity by spirometry. Sputum culture in exacerbations identifies causative bacteria. CT chest assesses emphysema. Arterial blood gas (ABG) measures hypoxia and hypercapnia in severe disease. Diffusing capacity of the lungs for carbon monoxide (DLCO or TLCO) is reduced in emphysematous COPD — differentiating COPD from asthma where DLCO is typically normal or elevated. High-resolution CT (HRCT) chest characterises emphysema distribution and detects bronchiectasis complicating chronic bronchitis. Alpha-1-antitrypsin deficiency testing (serum protein and genotyping) should be offered to all patients with COPD under age 45 or without clear smoking history.

Acute bronchitis: antibiotics are NOT indicated in most cases — 90% are viral. Symptomatic treatment: paracetamol or ibuprofen for fever/discomfort, adequate hydration, honey (evidence-based cough suppressant in adults and children over 1 year), over-the-counter cough medications. Inhaled bronchodilators (salbutamol) if wheeze is prominent. Chronic bronchitis: smoking cessation is the most effective intervention — it halves the rate of lung function decline. Short-acting bronchodilators (salbutamol, ipratropium), long-acting bronchodilators (tiotropium, salmeterol/formoterol), inhaled corticosteroids for combined therapy, pulmonary rehabilitation (12-week programme improves exercise capacity by 20-30%), and long-term oxygen therapy (LTOT) if resting SpO2 is consistently below 88%. Roflumilast (a phosphodiesterase-4 inhibitor) reduces exacerbation frequency in severe COPD with chronic bronchitis and FEV1 below 50% predicted. Azithromycin prophylaxis (250 mg daily or 500 mg three times weekly) reduces exacerbation frequency in COPD patients with frequent exacerbations — though risk of cardiac arrhythmia and macrolide resistance requires careful patient selection. Lung volume reduction surgery or bronchoscopic lung volume reduction (coils, valves) in carefully selected emphysematous patients improves exercise capacity and quality of life.

Acute bronchitis rarely causes complications in healthy adults. Secondary bacterial pneumonia can be life-threatening in elderly or immunocompromised patients. In children, acute bronchiolitis from RSV can cause respiratory failure. Pertussis (whooping cough) presenting as bronchitis in adults is highly contagious and life-threatening in unvaccinated infants. Chronic bronchitis without smoking cessation leads to progressive COPD, increasing risk of frequent exacerbations, hospitalisation, cor pulmonale, and ultimately respiratory failure. COPD is the 3rd leading cause of death globally, killing 3.23 million people annually.

Acute bronchitis prevention: wash hands frequently; get annual influenza vaccination; stay away from people with respiratory infections; avoid smoking (active and passive). Chronic bronchitis prevention: never start smoking — if you smoke, quit immediately and ask your GP for support (nicotine replacement therapy, varenicline, bupropion). Reduce indoor air pollution from cooking fires and biomass fuels. Use respiratory protection in dusty or chemically hazardous occupations. Annual influenza vaccination and pneumococcal vaccination are strongly recommended in those with existing lung disease. Pulmonary rehabilitation improves exercise capacity and quality of life.

Acute bronchitis is usually a self-limiting viral illness that resolves without antibiotics in 2–3 weeks. See your GP if: cough lasts more than 3 weeks; you cough up blood (haemoptysis); you develop breathlessness, chest pain, or high fever; or you are elderly, immunocompromised, or have pre-existing lung or heart disease. Seek emergency assessment for: rapidly worsening breathlessness, confusion, lips or fingernails turning blue (cyanosis), respiratory rate above 30 breaths per minute, or inability to complete sentences — these may indicate pneumonia, COPD exacerbation, or respiratory failure. People with known COPD who develop a significant increase in sputum volume or change in sputum colour, worsening breathlessness, or increased wheeze should contact their respiratory team or GP for early treatment — COPD exacerbations treated early prevent hospitalisation.