For either acute bronchitis or chronic bronchitis, signs and symptoms may include:
- Production of mucus (sputum), which can be clear, white, yellowish-gray or green in color — rarely, it may be streaked with blood
- Shortness of breath
- Slight fever and chills
- Chest discomfort
If you have acute bronchitis, you may have a nagging cough that lingers for several weeks after the inflammation resolves. Chronic bronchitis is defined as a productive cough that lasts at least three months, with recurring bouts occurring for at least two consecutive years.
If you have chronic bronchitis, you're likely to have periods when your signs and symptoms worsen. At those times, you may have acute bronchitis on top of your chronic bronchitis.
When to see a doctor
See your doctor if your cough:
- Lasts more than three weeks
- Prevents you from sleeping
- Is accompanied by fever higher than 100.4 F (38 C)
- Produces discolored mucus
- Produces blood
- Is associated with wheezing or shortness of breath
Acute bronchitis is usually caused by viruses, typically the same viruses that cause colds and flu (influenza). Antibiotics don't kill viruses, so this type of medication isn't useful in most cases of bronchitis.
The most common cause of chronic bronchitis is smoking cigarettes. Air pollution and dust or toxic gases in the environment or workplace also can contribute to the condition.
Factors that increase your risk of bronchitis include:
- Cigarette smoke. People who smoke or who live with a smoker are at higher risk of both acute bronchitis and chronic bronchitis.
- Low resistance. This may result from another acute illness, such as a cold, or from a chronic condition that compromises your immune system. Older adults, infants and young children have greater vulnerability to infection.
- Exposure to irritants on the job. Your risk of developing bronchitis is greater if you work around certain lung irritants, such as grains or textiles, or are exposed to chemical fumes.
- Gastric reflux. Repeated bouts of severe heartburn can irritate your throat and make you more prone to developing bronchitis.
Although a single episode of bronchitis usually isn't cause for concern, it can lead to pneumonia in some people. Repeated bouts of bronchitis may indicate that you're developing chronic obstructive pulmonary disease (COPD).