In simple terms, bronchitis refers to the inflammation of cells in the inner lining of the bronchi – the passages in the lower respiratory tract that conduct air into the lungs.
The bronchi are tubes through which air enters and exits the lungs. The trachea (windpipe) divides into the right and left bronchus, which after entering the respective lobes of the lungs, further branch into bronchioles.
The bronchi are mainly passageways for air to reach the innermost cells of the lungs, where the exchange of oxygen and carbon dioxide takes place.
In normal circumstances, the bronchial cells produce a small amount of mucus, which helps
- to moisturise the inhaled air and
- to trap viruses and bacteria before they enter the lungs.
- They also have small hair-like structures which help to move the mucus and prevent any foreign object from entering the lungs.
In the presence of infection, the cells of the bronchi become inflamed and produce more mucus, which is then expelled by coughing.
Bronchitis may be:
- Acute bronchitis: this is a more common condition than the chronic type and is used interchangeably with the term bronchitis. It lasts for a couple of weeks and is contagious, especially during the first week, because it usually has a viral origin.
- Chronic bronchitis is a more serious condition than the acute type, lasts for a few months and recurs every year. It is not contagious because it is usually a result of irritation to the air passages leading to the lungs.
Symptoms
Acute bronchitis shows up with most of the symptoms of common cold and the flu.
Some of the usual complaints are:
- A runny and sometimes stuffy nose with a sore throat, and a mild fever
- Cough with or without sputum, which will be yellow or greenish in colour
- Congestion and tightening of chest
- A wheezing or whistling sound while breathing because less air passes through the bronchi when they are swollen
- Difficulty in breathing
- Tiredness
The symptoms usually subside after 10-15 days, except for the cough which may persist for a few weeks.
People having chronic bronchitis have a consistent and persistent cough, usually with sputum.
Causes
Bronchitis or acute bronchitis is a lower respiratory tract infection. It is usually a progression of a common cold or a flu attack. It is more severe than a flu attack but not as serious as pneumonia, which can be life-threatening.
In most cases, it is the result of a viral infection which is transmitted by close contact with someone who has the virus.
It could also be an acute reaction to something toxic, like fumes, tobacco smoke or dust.
The viral infection spreads via droplets in the air (by sneezing or coughing) or by hands not being washed thoroughly after touching infected surfaces. It is a common occurrence with children and seen more often in winter.
Bronchitis may affect certain people more often:
- Smokers with a history of long-term tobacco smoking are prone to chronic bronchitis.
- People who are asthmatic or have other allergies.
- People who have a weak immune system.
Chronic bronchitis is typically seen in people over 40 years of age and invariably affects people engaged in specific occupations, like workers of coal mines, chemical and textile factories. These people are naturally exposed to toxic substances in the inhaled air for a prolonged period.
Diagnosis
- A routine history, accurate description of the cough and mucus and a physical examination are enough to diagnose bronchitis.
- Wheezing sounds in the lungs
- Microscopic examination of mucus and blood can reveal any bacterial infection
- A chest X-ray may be taken to rule out pneumonia
- Lung function tests can be done to rule out damage to the inner cells of the lungs.
Treatment
Acute bronchitis is self-limiting and does not require extensive treatment. It will run its course lasting two to three weeks, and the individual recovers. It can be managed with good home care and following some common guidelines:
- Have adequate rest, and consume plenty of fluids and water
- If needed, have anti-cough medicine (`cough syrups’) to suppress the cough reflex.
- Alternatively, medicines like expectorants make the mucus thinner and easier to cough out.
- NSAIDs may be taken for pain relief.
- Steam inhalation and hot showers can loosen the mucus.
People suffering from chronic bronchitis are prescribed inhalers containing bronchodilators to open the air passages, and steroids to control the swelling and mucus formation.
Antibiotics are prescribed only if it is confirmed to be a bacterial infection.
Chronic bronchitis cannot be cured easily, but the symptoms can be controlled to a great extent by staying away from triggers that cause coughing. It also helps to wear a mask when working in certain industries and factories that have high levels of toxins in the air.
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