The bronchi are the two main airways that branch down from the trachea (the airway that starts in the back of the throat and goes into the chest). When the parts of the walls of the bronchi become swollen and tender (inflamed), the condition is called bronchitis. The inflammation causes more mucus to be produced, which narrows the airway and makes breathing more difficult.
There are several types of bronchitis:
- Acute bronchitis can last for up to 90 days
- Chronic bronchitis can last for months or sometimes years. If chronic bronchitis decreases the amount of air flowing to the lungs, it is considered to be a sign of chronic obstructive pulmonary disease.
- Infectious bronchitis usually occurs in the winter due to viruses, including the influenza virus. Even after a viral infection has passed, the irritation of the bronchi can continue to cause symptoms. Infectious bronchitis can also be due to bacteria, especially if it follows an upper respiratory viral infection. It is possible to have viral and bacterial bronchitis at the same time.
- Irritative bronchitis (or industrial or environmental bronchitis) is caused by exposure to mineral or vegetable dusts or fumes from strong acids, ammonia, some organic solvents, chlorine, hydrogen sulfide, sulfur dioxide and bromine
Symptoms will vary somewhat depending on the underlying cause of the bronchitis. When the bronchitis is due to an infection the symptoms may include:
- A slight fever of 100 to 101°F with severe bronchitis. The fever may rise to 101 to 102°F and last three to five days even after antibiotics are started.
- A runny nose
- Aches in the back and muscles
- Coughing that starts out dry is often the first sign of acute bronchitis. Small amounts of white mucus may be coughed up if the bronchitis is viral. If the color of the mucus changes to green or yellow, it may be a sign that a bacterial infection has also set in. The cough is usually the last symptom to clear up and may last for weeks.
- Feeling tired
- Shortness of breath that can be triggered by inhaling cold, outdoor air or smelling strong odors. This happens because the inflamed bronchi may narrow for short periods of time, cutting down the amount of air that enters the lungs. Wheezing, especially after coughing, is common.
- Sore throat
Causes and Risk Factors
An infection or irritating substances, gases or particles in the air can cause acute bronchitis. Smokers and people with chronic lung disease are more prone to repeated attacks of acute bronchitis. This is because the mucus in their airways doesn't drain well. Others at risk of getting acute bronchitis repeatedly are people with chronic sinus infections or allergies; children with enlarged tonsils and adenoids; and people who don't eat properly.
To diagnose bronchitis, a physician performs a physical examination, listens for wheezing with a stethoscope and evaluates symptoms - making sure they are not due to pneumonia. A sample of sputum from a cough may be examined because its color - clear or white versus yellow or green - may suggest whether the bronchitis is due to a viral infection or a bacterial infection, respectively. A chest X-ray may be needed to rule out pneumonia, and if the cough lasts more than two months, a chest X-ray may be done to rule out another lung disease, such as lung cancer.
Depending on the symptoms and cause of the bronchitis, treatment options include:
- Antibiotics may be ordered to treat acute bronchitis that appears to be caused by a bacterial infection or for people who have other lung diseases that put them at a greater risk of lung infections
- Bronchodilators, which open up the bronchi, may be used on a short-term basis to open airways and reduce wheezing
- Cool-mist humidifiers or steam vaporizers can be helpful for wheezing or shortness of breath. Leaning over a bathroom sink full of hot water with a towel loosely draped over the head can also be help open the airways.
- Corticosteroids given in an inhaler are sometimes prescribed to help the cough go away, reduce inflammation and make the airways less reactive. They are most often given when the cough remains after the infection is no longer present.
- Cough medicines should be used carefully. While they can be helpful to suppress a dry, bothersome cough, they should not be used to suppress a cough that produces a lot of sputum. When the cough is wet, expectorants can help thin the secretions and make them easier to cough up. When a lot of mucus is present, coughing is important to clear the lungs of fluid.
- For viral bronchitis, antibiotics will not be effective. If influenza causes the bronchitis, treatment with antiviral drugs may be helpful.
- Over-the-counter pain relievers, such as aspirin, acetaminophen or ibuprofen, can be used for pain relief and fever reduction. Children with bronchitis should not be given aspirin; instead they should take acetaminophen or ibuprofen.
- Plenty of fluids - enough to keep the urine pale (except for the first urination of the day, when it is usually darker)
- Rest, especially if a fever is present