Acute Bronchitis

What Is It?

Acute bronchitis is an inflammation of the lining of the bronchial tubes, the hollow air passages that connect the lungs to the windpipe (trachea). The inflammation can be caused by an infection or by other factors that irritate the airways, such as cigarette smoking, allergies and exposure to fumes from some chemicals.

Acute bronchitis caused by an infection usually starts with an upper respiratory illness, such as the common cold or flu (influenza), that spreads from your nose and throat down into the airways. Acute bronchitis does not affect the lungs like pneumonia does. Pneumonia shows up on a chest X-ray, but acute bronchitis does not.

Most cases of acute bronchitis are caused by viruses, although the condition also can be caused by bacteria.

Acute bronchitis is very common, affecting approximately 5 percent of the U.S. population each year.

Symptoms

The main symptom of acute bronchitis is a cough. The cough can be dry or it can produce sputum, the mucus-like substance brought up from the lungs. The sputum may be clear, cloudy, brown, yellow or greenish. Other symptoms can include wheezing, chest tightness or pain, shortness of breath, sore throat, nasal congestion, fever and tiredness.

Diagnosis

To diagnose acute bronchitis, your health care provider will ask about your medical history, especially whether you recently have had an upper respiratory infection. Your doctor also will listen to your chest with a stethoscope to try to detect sounds of wheezing or blocked airways. The level of oxygen in your blood may be tested using a small device that closes gently over a finger. If your health care provider hears any suspicious lung sounds during the physical examination, or if your oxygen level is lower than normal, he or she may order a chest X-ray to check for pneumonia.

Expected Duration

Most cases of acute bronchitis go away without treatment within five days, although coughing usually lasts seven to 10 days. In some cases, coughing continues for weeks or even months after the infection is gone because the bronchial linings are still irritated and may become narrow, as in asthma. Inhalers can help to treat the cough in these cases. When bronchitis comes back frequently or occurs most days of a month for at least three months of a year for two years, it is called chronic bronchitis, which often is related to smoking.

Prevention

There is no way to prevent all cases of acute bronchitis. However, the risk of bronchitis and complications can be reduced by not smoking, and by getting flu shots to reduce the risk of getting the flu, which can lead to acute bronchitis.