Alternative Names smoker's cough, COPD, chronic obstructive pulmonary disease
Definition Chronic bronchitis is an ongoing inflammation of the breathing tubes. It is almost always the result of long-term smoking. The official definition of chronic bronchitis requires coughing up phlegm most days for at least 3 months of the year for at least 2 years in a row.
What is going on in the body? Chronic bronchitis results from long-term exposure of the airways to irritants from tobacco smoke, air pollution, and other sources. These irritants cause the airways to secrete excess mucous and to become inflamed. With time, the inflammation becomes widespread. The cells lining the airways change, and the glands that produce the mucous become enlarged. Ultimately, inflammation and excess mucous combine to cause a cough that produces sputum, or phlegm, almost every day.
What are the signs and symptoms of the condition? Every person with chronic bronchitis will have:
cough
mucous production
Less commonly, people with chronic bronchitis may develop:
fever
shortness of breath
breathlessness with exertion
What are the causes and risks of the condition? Some of the factors that increase a person's risk for chronic bronchitis include:
smoking
untreated lung infections
previous viral infection of the lungs
toxic inhalation exposure
Most cases of chronic bronchitis occur in long-term cigarette smokers. More than half the middle-aged men who smoke a pack or more of cigarettes a day have chronic bronchitis. The chance of getting chronic bronchitis increases both with age and the number of cigarettes smoked.
What can be done to prevent the condition? Giving up smoking would prevent most cases of chronic bronchitis. Between 80% and 90% of chronic bronchitis results from smoking. Only a small minority of cases can be blamed on general air pollution or work-related exposures to dust.
How is the condition diagnosed? Chronic bronchitis is diagnosed by the person's history. A chronic cough with mucous production and long-time cigarette smoking make this diagnosis very likely. Chest X-rays may be done to exclude other serious diseases, such as pneumonia or lung cancer.
What are the long-term effects of the condition? With progressive chronic bronchitis, the person can expect:
increased difficulty breathing
increased risk of lung infections, or pneumonia
What are the risks to others? There are few risks to other people living in the same household. The main danger is the exposure to second-hand smoke from someone whose chronic bronchitis is caused by cigarette smoking.
What are the treatments for the condition? The main treatment for chronic bronchitis is to eliminate any irritants. In order to see any improvement, the person must stop smoking. It is also important to stop exposure to any dust, dirt, or fumes. Once the irritants have been eliminated, chronic bronchitis will usually improve on its own. Very advanced chronic bronchitis may not be reversible, but stopping smoking will keep it from worsening.
Some people improve with regular corticosteroid treatment. Those who do not improve after a trial of corticosteroids may not be continued on long-term treatment, as the side effects may outweigh the benefits.
In a few people, treatment with bronchodilators produces an improvement in lung function tests of 10% or more. Bronchodilators, such as salbutamol, are used to widen the airways in reversible airway diseases like asthma. They are often ineffective in chronic bronchitis or emphysema, another serious lung disease related to smoking.
Most people will benefit from rehabilitation therapy to enable them to use their energy more efficiently, or in a way that requires less oxygen. Some people may require oxygen therapy. This has been shown to improve survival, especially in those with advanced disease.
What are the side effects of the treatments? Side effects depend on which medications are used. Bronchodilators can cause a rapid heart rate and trembling of the hands.
Corticosteroids can predispose people to infections and may cause many other medical problems if used for long term treatment. They are only used in people who show good responses to the treatment.
What happens after treatment for the condition? People who quit smoking and eliminate other exposures to irritants will usually see an improvement in their chronic bronchitis, with less coughing and less mucous production. These people will probably be able to discontinue most of the medication used to treat their bronchitis. Those who have very severe chronic bronchitis may not see any improvement, but their disease should stop getting worse.
How is the condition monitored? The best guide to the effectiveness of treatment is the number of days the person goes without coughing up mucous. Ongoing improvement usually leads to much longer cough-free intervals. For those whose coughing continues, various lung function tests may be used to determine how well the lungs and airways are working.
Author: Reviewer: eknowhow Medical Review Panel Editor: Dr John Hearne Last Updated: 16/09/2004 Contributors Potential conflict of interest information for reviewers available on request
