Bronchitis happens when a virus, bacteria, or irritant particles trigger an inflammation of the bronchial tubes. There are two main types of bronchitis: acute and chronic.
Acute bronchitis is usually caused by infections. These infections cause the bronchial tubes to become inflamed and produce excess mucus, making it difficult to breathe. Such infections include:
- Viral infection: Viruses cause 85 to 95 percent of acute bronchitis cases in adults. The same viruses that cause the common cold or flu can cause acute bronchitis.
- Bacterial infection: In rare cases, bacterial bronchitis can develop after a viral infection of bronchitis. This can result from infections by bacteria such as Mycoplasma pneumoniae, Chlamydia pneumoniae, and Bordetella pertussis (which causes whooping cough).
Other lung conditions: People with chronic bronchitis or asthma sometimes develop acute bronchitis. In these cases, acute bronchitis isn’t likely to be contagious because it’s not caused by an infection.
Chronic bronchitis, on the other hand, is usually caused by long-term exposure to irritants: Breathing in irritants such as smoke, smog, or chemical fumes can cause inflammation in your trachea and bronchial tubes. The most common cause is smoking, but not everyone with bronchitis is a smoker.
Other factors that can contribute to the development of bronchitis include:
- Long term exposure to air pollution, dust, and fumes from the environment
- Genetic factors
- Repeated episodes of acute bronchitis
- A history of respiratory disease or gastroesophageal reflux disease (GERD)
- A weakened immune system
- Exposure to certain chemicals or pollutants
- Certain medications, such as beta-blockers and aspirin
- Chronic obstructive pulmonary disease (COPD)
- People with asthma or allergies have a higher risk of both types of the disease.
If you have symptoms of bronchitis, it is important to see a doctor for a proper diagnosis and treatment. In some cases, bronchitis can lead to serious complications, such as pneumonia, if left untreated.