Symptoms of acute bronchitis usually begin 3 to 4 days after an upper respiratory infection, such as a cold or influenza (flu). Symptoms usually include:

• A cough, which is the main symptom of acute bronchitis. It may be dry at first (does not produce mucus) and after a few days may bring up mucus from the lungs (productive cough). The mucus may be clear, yellow, or green. Occasionally, small streaks of blood may be present.
• A mild fever, usually less than 101 F. A higher fever may indicate pneumonia.
• A general feeling of tiredness.
• A sensation of tightness, burning, or dull pain in the chest under the breastbone that usually is worse when breathing deeply or coughing.
• Whistling noises (wheezing) when breathing, especially during physical exertion.
• Hoarseness.

Most cases of acute bronchitis in otherwise healthy people last only 2 to 3 weeks. However, more than 20% of people with acute bronchitis have a cough that lasts more than 4 weeks.²

Often it is hard to tell the difference between viral and bacterial forms of acute bronchitis, and many conditions have symptoms similar to acute bronchitis, such as asthma and pneumonia. Because pneumonia can be a serious complication, it is important to know the differences between acute bronchitis and pneumonia, such as a fast heart rate with pneumonia.