Bronchitis is an inflammation of the airways between the windpipe and the lungs (bronchial tubes). The lining of these tubes produces large amounts of mucus, triggering a lingering cough. About 1 in 20 people in North America suffers from chronic bronchitis. Women are more at risk than men.
There are two types of bronchitis:
Acute bronchitis comes on rapidly, usually after a virus has invaded the upper respiratory tract. Sometimes there is a bacterial infection as well. Viruses most likely to trigger acute bronchitis are those responsible for influenza (the flu) or the common cold. The germs that cause measles and whooping cough can also cause acute bronchitis. In these cases, it is called acute infectious bronchitis. The condition is called acute irritative bronchitis when it is caused by inhaling dust, fumes, or smoke.
Chronic bronchitis is defined as a mucus-producing cough that lasts for at least 3 months in 2 consecutive years. The most important cause by far is smoking. Exposure to some pollutants can also contribute to chronic bronchitis. A growing number of specialists believe that some kind of infection is a necessary final trigger of chronic bronchitis.
Typically, people with chronic bronchitis are smokers over 45 years of age. Certain jobs such as coal mining, welding, asbestos work, and grain handling also increase the risk of developing bronchitis.
Symptoms and Complications
Persistent coughing accompanied by mucus or phlegm is the most obvious symptom of bronchitis. Lung congestion and wheezing are also common.
Acute bronchitis usually starts out as a dry cough, but within a few hours or days the cough starts to produce thick mucus. This phlegm typically has a yellowish or greenish colour. Wheezing after coughing is usual, and there might be some chest pain as well. Other symptoms are similar to that of a common cold, such as muscle aches, tiredness, and sore throat. A mild fever of about 38.5°C (101°F) may last about 4 days. A higher temperature, or a fever that isn't gone within a week, may suggest a bacterial infection such as pneumonia. It's important to see a doctor in this situation.
Chronic bronchitis features regular coughing and spitting up of large amounts of thick mucus. This mucus can partly block the airways, making breathing difficult. The condition is often dismissed as smoker's cough. The coughing is often ignored until the lungs have already been damaged, resulting in chronic obstructive pulmonary disease (COPD). This can lead to a chronic lack of oxygen. Signs such as blue lips and nail beds may be noticed. People with this condition tend to become sedentary. The mucus in the airways creates a good environment for viruses and bacteria to breed. This makes people with chronic bronchitis and COPD more prone to other infections such as pneumonia.
It's important to be aware that symptoms of chronic bronchitis can suddenly get worse. If your medication no longer seems to be effective, see your doctor immediately.
Making the Diagnosis
Acute bronchitis is diagnosed by a doctor after a physical examination and discussion of your symptoms. This diagnosis is likely if you have a persistent cough, are spitting up yellow or green mucus, and have recently had a lung infection or a cold.
Chronic bronchitis is also diagnosed after your doctor has done a careful physical exam and has asked about the overall history of your health. Your doctor may want you to have pulmonary function tests to assess how well your lungs are working.
In either case, if your doctor suspects other problems such as emphysema, a chest X-ray will be ordered. Sputum samples may also be analysed to identify any infectious organisms in the airways, although these are less useful.
Treatment and Prevention
For acute (infectious) bronchitis:
- Antibiotics are normally only prescribed if the bronchitis is caused by bacteria. If a virus is the problem, the infection will generally go away by itself.
- Over-the-counter painkillers are used to control the fever symptoms of a viral infection. Children should never take ASA* (acetylsalicylic acid) for a viral infection of the respiratory tract. It can cause Reye's syndrome, which is a rare and lethal inflammation of the brain.
- Cough medications used may be suppressants that control the cough, or expectorants that thin the bronchial secretions.
- Bronchodilators are inhaled medications that help open up the airways. They are usually taken as a "puffer" (metered-dose inhaler) or as a mist used with a mask (nebuliser).
Non-medication remedies for acute bronchitis include:
- drinking lots of fluids - this makes mucus easier to get rid of
- using a cool or warm moist-air humidifier to help thin the mucus blocking the air passages
For chronic bronchitis:
- Inhaled bronchodilators and corticosteroids used regularly may open the airways, decrease inflammation, and improve health-related quality of life.
- Anticholinergic medications may help reduce the amount of coughing.
- Corticosteroids pills such as prednisone are sometimes given when chronic bronchitis suddenly becomes worse - these medications help reduce the inflammation and swelling of the airways.
Non-medication remedies for chronic bronchitis include:
- drinking plenty of fluid, which help to thin out the mucus so it is easier to get rid of
- using a cool or warm moist-air humidifier to thin the mucus blocking the air passages (humidifiers should be cleaned according to the manufacturer's directions to make sure bacteria or mould does not build up inside the machine)
- exercising regularly
- in some cases, taking oxygen therapy - this may be recommended for severe chronic bronchitis, especially when the symptoms suddenly worsen (many chronic bronchitis sufferers find that "home oxygen therapy" is helpful when they have difficulty breathing: this therapy is only useful if a measurement of oxygenation shows that the oxygen level in your blood is low)
If you already have chronic bronchitis and there has been some damage to the airways, quitting smoking slows down the disease and also lessens the chances of getting lung cancer. Seeking counselling from a health professional and joining a support group are the best ways to help you quit smoking.
Quitting smoking is also the best way to prevent bronchitis. Another important preventive measure is to be vaccinated against influenza and pneumonia. These vaccinations are recommended for seniors, people with certain medical conditions (e.g., diabetes, heart disease), and everyone with chronic bronchitis or COPD.