Is Bronchitis Contagious: When It Spreads and When It Doesn't

Bronchitis is inflammation of the mucous membrane of the bronchi, the cartilaginous tubes running from the trachea to the pulmonary alveoli (Wikipedia). Contagiousness depends not on the name of the disease but on its cause. Acute bronchitis is most often caused by infection, while chronic bronchitis is caused by irritation of the airways (Wikipedia, MedlinePlus).

Is bronchitis contagious or not: a short answer

Acute bronchitis in most cases has an infectious nature (Wikipedia). Since the main cause is viruses, the disease is most often contagious (Wikipedia). Pathogens spread through coughing and sneezing (National Health Service). Chronic bronchitis is not an infection: it is a type of COPD, chronic obstructive pulmonary disease (MedlinePlus).

Why acute bronchitis is most often viral and how it is transmitted

Among the pathogens are influenza A and B viruses, parainfluenza, respiratory syncytial virus, human metapneumovirus, rhinoviruses, adenoviruses, and coronaviruses; the main ones are influenza viruses (Wikipedia). Bacteria as a cause of acute bronchitis are much less common (Wikipedia). The disease usually occurs in the winter months and is associated with respiratory viruses (Wikipedia). The infections that cause bronchitis are transmitted through coughing and sneezing.

Bacterial and purulent bronchitis: are they contagious

There are known cases of bronchitis due to Chlamydophila pneumoniae, Bordetella pertussis in vaccinated people, and Mycoplasma pneumoniae (Wikipedia). The bacterial cause is determined by a doctor. Sputum may be clear, white, yellowish-gray, or green, rarely with blood streaks; in later stages, it may be purulent (Wikipedia).

When bronchitis is not contagious: chronic and allergic

Chronic bronchitis is inflammation and irritation of the bronchial tubes with accumulation of mucus (MedlinePlus). The cause is prolonged exposure to irritants: cigarette smoke, secondhand smoke, air pollution, chemical fumes, and dust (MedlinePlus). Tobacco smoking is associated with more than 90% of chronic bronchitis cases (Wikipedia). Up to 75% of people with chronic bronchitis smoke or have smoked; in most, symptoms begin at age 40 and older (MedlinePlus). Smoking, asthma, and allergies are risk factors for both acute and chronic bronchitis (Wikipedia). An exacerbation of chronic bronchitis is considered a separate disease distinct from acute bronchitis (Wikipedia). People with chronic bronchitis are more likely to get respiratory infections, such as colds and flu (MedlinePlus). The chronic inflammation itself is not transmitted from person to person.

How long a patient can be a source of infection

In acute bronchitis, cough and sputum production usually last from 1 to 3 weeks, and in most cases the disease resolves on its own (Wikipedia). Bronchitis usually improves in about 3 weeks (National Health Service). A cough lasting longer than 3 weeks is a reason to consider other diagnoses, such as post-infectious cough (Wikipedia). The exact period during which a patient remains a source of infection is determined by a doctor; the course of the disease lasts from 1 to 3 weeks. Residual cough after an infection is considered separately (Wikipedia).

When to see a doctor for bronchitis

Consultation is needed if symptoms do not improve (National Health Service). A separate group is people with conditions that increase vulnerability to bronchitis, such as diabetes (National Health Service). You should urgently make an appointment or seek medical help in the following cases (National Health Service):

• cough lasts longer than 3 weeks and does not ease;
• blood or blood streaks appear in the sputum;
• there is chest pain — intermittent, on breathing or coughing;
• age over 65, pregnancy, a long-term condition (diabetes, heart, lung, or kidney disease), or weakened immunity;
• severe weakness, shortness of breath.

Shortness of breath, rapid breathing, and tachycardia in acute bronchitis may indicate possible pneumonia (Wikipedia).

Bronchitis alone is not a reason to call an ambulance. Call 103 or 112 if a person cannot breathe — gasping, wheezing, and unable to speak; lips or skin have become very pale, blue, or gray; sudden confusion; a child cannot be woken or is lethargic (National Health Service).

This material is for reference: it describes signs and does not replace a doctor's consultation.

This content is for reference and does not replace a doctor's consultation. Medical disclaimer