Bronchitis is an inflammation or swelling of the bronchial tubes (bronchi), the air passages between the mouth and nose and the lungs.
More specifically, bronchitis describes a condition where the lining of the bronchial tubes becomes inflamed.
Individuals with bronchitis have a reduced ability to breathe air and oxygen into their lungs; also, they cannot clear heavy mucus or phlegm from their airways.
This article will cover the causes, symptoms, treatments, and prevention of bronchitis.
Fast facts about bronchitis
Here are some key points about bronchitis. More detail and supporting information is in the main article
- Bronchitis can be caused by viruses, bacteria, and other particles that irritate the bronchial tubes
- Acute bronchitis is a short-term illness that often follows a cold or viral infection
- Chronic bronchitis is a long-term illness and can be the result of environmental factors or extended illness
- Cigarette smoking is the most common cause of chronic bronchitis
- Chest X-ray, lung function testing, and blood testing are used to diagnose bronchitis
What is bronchitis?Bronchitis may be acute or chronic:
Acute bronchitis is a shorter illness that commonly follows a cold or viral infection, such as the flu. It consists of a cough with mucus, chest discomfort or soreness, fever, and, sometimes, shortness of breath. Acute bronchitis usually lasts a few days or weeks.
Chronic bronchitis is a serious, ongoing illness characterized by a persistent, mucus-producing cough that lasts longer than 3 months out of the year for more than 2 years. People with chronic bronchitis have varying degrees of breathing difficulties, and symptoms may get better and worse during different parts of the year.
If chronic bronchitis occurs with emphysema, it may become chronic obstructive pulmonary disease (COPD).
Causes of bronchitis
Bronchitis is caused by the inflammation of the bronchial tubes, by viruses, bacteria, or other irritant particles.
Causes of acute bronchitis
Bronchitis is usually caused by viral infection.
Acute bronchitis is normally caused by viruses, typically those that also cause colds and flu.
It can also be caused by bacterial infection and exposure to substances that irritate the lungs, such as tobacco smoke, dust, fumes, vapors, and air pollution.
Causes of chronic bronchitis
Chronic bronchitis is caused by repeated irritation and damage of the lung and airway tissue.
Smoking is the most common causes of chronic bronchitis, with other causes including long-term exposure to air pollution, dust and fumes from the environment, and repeated episodes of acute bronchitis.
Symptoms of bronchitis
Bronchitis is characterized by persistent coughing.
Signs and symptoms of both acute and chronic bronchitis include:
- Persistent cough, which may produce mucus
- Low fever and chills
- Chest tightening
- Sore throat
- Body aches
- Blocked nose and sinuses
One of the main symptoms of acute bronchitis is a cough that lasts for several weeks. It can sometimes last for several months if the bronchial tubes take a long time to heal fully.
It is common for the symptoms of chronic bronchitis to get worse two or more times every year, and they are often worse during the winter months.
Diagnosis of bronchitis
The doctor will ask about the symptoms and in particular the cough. They may also ask about the patient's medical history, whether they have recently suffered from a cold or flu, whether they smoke, or whether they have recently been exposed to substances such as dust, fumes, vapors, or air pollution.
A doctor will usually use a stethoscope to listen for any abnormal sounds in the lungs. They may also examine mucus or test the oxygen levels in the blood, and may recommend a chest X-ray, pulmonary lung function test, or blood tests.
Treatments for bronchitis
People suffering from bronchitis are usually instructed to rest, drink fluids, breath warm and moist air, and take OTC cough suppressants and pain relievers to manage symptoms and ease breathing.
Many cases of acute bronchitis go away without any specific treatment, but there is no cure for chronic bronchitis. To keep bronchitis symptoms under control and relieve symptoms, doctors might prescribe:
- Cough medicine - although coughing should not be completely suppressed as this is an important way to bring up mucus and remove irritants from the lungs.
- Bronchodilators - these open the bronchial tubes and clear out mucus.
- Mucolytics - these thin or loosen mucus in the airways, making it easier to cough up sputum.
- Anti-inflammatory medicines and glucocorticoid steroids - these are for more persistent symptoms to help decrease chronic inflammation that may cause tissue damage.
- Oxygen therapy - this helps improve oxygen intake when breathing is difficult.
- Pulmonary rehabilitation program - this includes work with a respiratory therapist to help improve breathing.
- Antibiotics - these are effective for bacterial infections, but not for viral infections. They may also prevent secondary infections.
Additional behavioral remedies include:
- Removing the source of irritation to the lungs - for example, by stopping smoking
- Using a humidifier - this can loosen mucus and relieve limited airflow and wheezing
- Exercise - this will strengthen the muscles involved in breathing
- Breathing exercises - for example, pursed-lip breathing that helps to slow breathing down
Complications of bronchitis
The most common complication of bronchitis is pneumonia; this occurs when the infection spreads deeper into the lungs. This infection causes the air sacs within the lungs (alveoli) to fill with fluid.
An estimated 5 percent of bronchitis cases lead to pneumonia.
Pneumonia is more likely to develop in older adults, smokers, people with diseases in other organs, and anyone with a reduced immune system.
As cigarette smoking is the most common cause of chronic bronchitis, avoiding smoking is one of the best ways to prevent it.
Although it is not always possible to prevent acute or chronic bronchitis, there are several measures that can help reduce the risk:
- Do not start smoking; quit smoking if you already smoke.
- Avoid lung irritants such as smoke, dust, fumes, vapors, and air pollution. If avoiding exposure is not possible, wear a mask that covers the nose and mouth.
- Wash hands often to limit exposure to germs and bacteria.
- Get a yearly flu vaccine.
- Get a pneumonia vaccine.
In a study in Lebanon, exposure to passive smoking at work was associated with almost double the risk of chronic bronchitis (an 89 percent increased risk), while passive smoking at home was associated with more than two-and-a-half times the risk of chronic bronchitis.
Living close to a busy road almost doubles the risk, as does heating the home with hot air conditioning rather than electric heating. Living close to a diesel-burning power plant has also been associated with a 62 percent increase in the risk of chronic bronchitis.