What is bronchitis?|
Bronchitis is the inflammation of the airways in the lungs. It can be acute or chronic.
Acute bronchitis is generally associated with a quick and complete recovery. In individuals with associated illnesses, the condition can be more aggressive and could result in complications such as pneumonia.
Chronic bronchitis is diagnosed when there is coughing with sputum for more than 3months in each of 2 consecutive years1, which is not related to other causes such as tuberculosis, lung cancer or heart disease. Chronic bronchitis, along with another lung disease called emphysema makes up chronic obstructive pulmonary disease (COPD).
What causes bronchitis?
Acute bronchitis is common in winter, and often develops after a common cold or other minor infections of the airways. Up to 90% of cases2 are caused by viruses, and bacteria being the other causes. The following factors can make someone more prone to bronchitis1:
- environmental pollutants
- having underlying chronic lung diseases (such as chronic sinusitis – inflammation of the sinuses, bronchiectasis – abnormally dilated airways)
- Allergic disorders
- chronic obstructive pulmonary disease
- children with enlarged tonsils
- exposure to chemical irritants (such as mineral dusts, fumes, acids, ammonia, solvents, chlorine, sulphur compounds, cigarette smoke, nitrogen dioxide)
Inflammation of the lining of the airways (Bronchi) leads to swelling and increase in white blood cells and secretions. Excess secretions are a feature of bronchitis, more so in the chronic form. In addition there tends to be contraction of the smooth muscle around the airways. This could lead to obstruction or blocking of the airways. The excess secretions are generally eliminated by coughing, producing sputum.
Bronchitis usually presents with features of a common cold, which progresses to a worsening cough, with sputum production. This tends to be associated with a fever and shortness of breath and a tight feeling in the chest, sometimes with wheezing. In the chronic form cough tends to be present over several months. Persistent fever, chills, increasing shortness of breath can suggest the development of a more severe infection of the lungs, such as pneumonia.
Acute bronchitis is relatively common, with about 1 case in every 20 people in one year. It is more common in men, children under age of 10 and men over age of 50 are more affected. Chronic bronchitis affects ¼ of people over the age of 45.3
Acute bronchitis is diagnosed clinically. However, chest x-ray may be useful to exclude other lung disease.2 Blood tests to check oxygen and carbon dioxide levels in the blood may be used if symptoms are severe or when there are other lung diseases. In patients who do not respond to treatment, it may be necessary to identify the organisms that cause infection by laboratory tests by culturing the sputum.
The diagnosis of chronic bronchitis is made mainly on the history of coughing with sputum production that tends to be chronic, in susceptible individuals.. Lung function tests assist to assess the status of the lungs. Blood tests may show an increase in the red blood cell count, which occurs, as the body puts out the response to cope with lowered oxygen levels.
Chest x-rays are important to exclude other causes but correlate poorly to the symptoms of chronic bronchitis.4
Rest, oral fluids, paracetamol and pain relief may be all that is required for acute bronchitis. When the patient has a fever and the sputum is yellow or green and