Symptoms and causes

Symptoms

For either acute bronchitis or chronic bronchitis, signs and symptoms may include:

  • Cough
  • Production of mucus (sputum), which can be clear, white, yellowish-gray or green in color — rarely, it may be streaked with blood
  • Fatigue
  • Shortness of breath
  • Slight fever and chills
  • Chest discomfort

If you have acute bronchitis, you might have cold symptoms, such as a mild headache or body aches. While these symptoms usually improve in about a week, you may have a nagging cough that lingers for several weeks.

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 cough or other symptoms worsen. At those times, you may have an acute infection on top of 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

Causes

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 cigarette smoking. Air pollution and dust or toxic gases in the environment or workplace also can contribute to the condition.

Risk factors

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.

Complications

Although a single episode of bronchitis usually isn't cause for concern, it can lead to pneumonia in some people. Repeated bouts of bronchitis, however, may mean that you have chronic obstructive pulmonary disease (COPD).