Acute Bronchitis

Acute bronchitis is an infection of the bronchial tree, which is a network made up of the tubes that carry air to and from the lungs.  When these tubes get infected, they swell and mucus forms.  This mucus makes it hard to breathe and must be removed; coughing and wheezing are the result.

Causes and Development

A healthy airway (left) and an airway damaged by Acute Bronchitis (right). The lining swells, thickens, and produces mucus.

Acute bronchitis is almost always caused by viruses that attack the lining of the bronchial tree and cause infection.  As your body fights back against these viruses, more swelling occurs and more mucus is made.  It takes time for your body to kill the viruses and heal the damage to your bronchial tubes.

In most cases, the same viruses that cause colds cause acute bronchitis.  Research has shown that bacterial infection is much less common in bronchitis than previously thought.  Very rarely, an infection caused by a fungus can lead to acute bronchitis.  The viruses that cause acute bronchitis are sprayed into the air or onto people's hands when they cough.  You can get acute bronchitis if you breathe in those viruses or transfer them from a contaminated hand to your mouth.

Signs and Symptoms

Sometimes the cough from acute bronchitis lasts for several weeks or months, generally because the bronchial tree is taking a long time to heal.  However, a cough that doesn't go away may be a sign of another problem, such as asthma or pneumonia.

Treatment and Prevention

Because acute bronchitis is usually caused by viruses, antibiotics (medicines that kill bacteria) usually do not help.  Even if you cough up mucus that is colored or thick, antibiotics probably won't help you get better any faster.

For some people with acute bronchitis, doctors prescribe medicines that are usually used to treat asthma.  These medicines can help open the bronchial tubes and clear out mucus.  They are usually given with an inhaler.  An inhaler sprays the medicine right into the bronchial tree.

Prognosis; Seek medical attention if...

Most cases of acute bronchitis will go away on their own after a few days.

You should call your doctor if:

• You continue to wheeze and cough for more than one month, especially at night or when you are active.
• You continue to cough for more than one month and sometimes have a bad tasting fluid come up into your mouth.
• You have a cough, you feel very sick and weak, and you have a high fever that doesn't go down.
• You cough up blood.
• You have trouble breathing when you lie down.
• Your feet swell.