What is bronchitis?

To answer the question “What is bronchitis?”, it is useful to first understand the structure of the lungs so that you can see how they are affected by this condition.

The lungs are comprised of two main branches called bronchi that carry air from the trachea to the smaller tubes (bronchioles). These bronchioles, in turn, lead to the alveoli in the lungs where gas exchange takes place into and out of the bloodstream.

Bronchitis¹ is an infection that typically occurs when the bronchial tubes become infected with a virus. Acute bronchitis accounts for 100 million ambulatory visits in the US each year and is one of the most common conditions encountered in an outpatient setting. Acute bronchitis occurs most frequently in the late fall and winter months.

Bronchitis is not to be confused with bronchiolitis which is an infection of the smaller bronchiole tubes which connect the bronchi with the alveoli.

A patient with bronchitis will have a reduced capacity to breathe air into the lungs and may also find it harder to remove mucus and phlegm from their airways.

There are two main forms of bronchitis: acute and chronic. Symptoms for both conditions are the same. They may include cough, fatigue, shortness of breath, slight fever and chills, discomfort, and the production of mucus (sputum). This mucus may be clear, white, yellow, or green.

Differences between acute and chronic bronchitis

Acute bronchitis² is sometimes known as a chest cold. It is much more common in winter and develops as a result of a cold or other respiratory infection from a virus or bacteria.

Acute bronchitis is contagious and can spread from person to person through infected droplet particles left in the air after sneezing or coughing. These droplets can survive on surfaces for up to 24 hours. Contact with the infected surface can also spread infection.

Fortunately, the symptoms of acute bronchitis are short-lived and typically resolve in 2-3 weeks. In most cases, treatment is not necessary with self-care techniques such as rest and plenty of fluids.

A patient may require acetaminophen or non-steroidal anti-inflammatory drugs (NSAIDs) for concurrent cold symptoms to relieve fever or pain. Patients usually improve within 7–10 days.

It is important to seek medical advice if you have any underlying health conditions, such as heart and lung disease (ie. asthma, heart failure, emphysema). You should also seek medical attention if you have new or worsened symptoms.

Chronic bronchitis³ is a more serious condition and is used to describe constant inflammation in the lining of the bronchi. This is frequently caused by air pollution or smoking. Chronic bronchitis is defined as a daily productive cough that lasts for three or more months of the year for two years in a row.

Chronic bronchitis is one of a number of conditions (including emphysema) that is collectively known as chronic obstructive pulmonary disease (COPD)⁴. The most common cause of COPD is smoking, which means COPD is not contagious because it is caused by long-term irritation of the airways.

Globally, 3 million people die each year from COPD, mainly in low- and middle-income countries. This number represents 6% of all deaths worldwide.

What’s the difference between bronchitis and pneumonia?

It is easy to confuse bronchitis with pneumonia as both conditions will show the same symptoms of chest heaviness, cough, fever, and fatigue.

The key difference between bronchitis and pneumonia⁵ is that bronchitis affects the bronchial tubes whereas pneumonia affects the alveoli where gas exchange takes place.

Pneumonia symptoms tend to be more severe and can be life-threatening, particularly in the elderly, or in vulnerable populations such as those with compromised immune systems.

Acute bronchitis symptoms

The main acute bronchitis symptoms⁶ consist of a persistent cough which can make it difficult to breathe. This may also bring up clear, yellow-grey or greenish mucus (phlegm).

Other symptoms include:

• a sore throat
• headache
• runny or blocked nose
• aches and pains
• tiredness
• shortness of breath (wheezing)- this is more common in long term chronic bronchitis

These acute bronchitis symptoms are similar to those of sinusitis or the common cold. If symptoms persist for a few weeks, this may be an indication of acute bronchitis.

The following symptoms may indicate a more serious condition:

• A severe cough or one which persists for more than a few weeks
• A high temperature lasting more than three days (this could indicate a secondary infection, such as the flu or pneumonia)
• Mucus streaked with blood
• The presence of other medical conditions such as asthma, emphysema, or heart disease
• Breathing has become increasingly difficult
• Suffering from recurrent bronchitis: With chronic bronchitis, there may be times when your cough or other symptoms worsen. This may indicate that you have acute bronchitis on top of your chronic condition.

Symptoms may also be accompanied by an infection in the throat and nasal passages (known as pharyngitis). Alternatively, the larynx (voicebox) may be affected. This is termed laryngitis.

Remember, it is always best to seek advice from your provider if you have any concerns about these or any other symptoms that you may be experiencing.

Bronchitis causes

Acute bronchitis may be caused by viruses that also cause the common cold and the flu. The most common viruses are rhinovirus, coronavirus, respiratory syncytial virus, influenza A and B, and parainfluenza virus.

In 5–15% of cases, and typically in people with underlying health problems, a bacterial infection may result in acute bronchitis. Mycoplasma pneumoniae, Chlamydia pneumoniae, and Bordetella pertussis are some of the most common pathogens involved.

Chronic bronchitis may be caused by cigarette smoking, air pollution, dust, or toxic gases in the workplace or the environment.

Risk factors for bronchitis

A risk factor is something that increases the likelihood of developing a particular condition.

The following are the main risk factors for bronchitis⁷:

• Cigarette smoke: Being an active smoker or having regular exposure to second-hand cigarette smoke places you at a higher risk of developing both acute and chronic bronchitis, in addition to a wide range of other lung conditions such as lung cancer and emphysema. Emphysema damages the air sacs (alveoli) inside the lungs. This is another COPD condition that is frequently associated with acute bronchitis.

• Low immune system: A compromised immune system may reduce your body’s capacity to fight off a new infection.

• Gastric reflux: Also known as gastroesophageal reflux disease (GERD). Recurrence of severe heartburn can irritate the throat and increase your chance of developing bronchitis.

• Age: Older adults, infants, and babies are more vulnerable to infection. A person with childhood respiratory diseases⁸ may be more at risk of developing bronchitis.

• Family history of lung disease: There may be a genetic predisposition to developing lung disease.

• Lung irritants in the workplace: your risk of developing acute bronchitis increases if you work with grains, textiles, or are exposed to smog or chemical fumes such as ammonia, strong acids, or chlorine. This is termed occupational bronchitis, and your condition usually improves once you remove yourself from these irritants.

• Working with infected animals: Sometimes viruses can jump from one species to another. This led to an epidemic of bird flu in 2005. Some of the victims also developed bronchitis.

• Close contact: Minimize contact with someone who has a cold or acute bronchitis. The virus spreads by droplet infection and can survive on surfaces for 24 hours after it has landed. Avoiding people who are infectious and practicing hand hygiene will help to reduce the spread of infection.

• Failure to receive age-appropriate immunizations: Following the immunization guidelines and vaccination schedules will strengthen your immune system and reduce the likelihood of developing infections that may lead to acute bronchitis.

• Underlying medical conditions: Other medical conditions such as heart disease or respiratory illnesses such as asthma may increase your risk of developing acute bronchitis.

Is acute bronchitis contagious?

Acute bronchitis is typically spread by a viral infection⁹ that can pass from person to person through direct contact (such as shaking hands) or indirect contact (such as touching a work surface or door handle contaminated with the virus).

Inhaling virus-containing particles that have been released by sneezing may also lead to infection. A patient may be contagious a few days before the symptoms appear and for as long as the symptoms remain.

How to stop the bronchitis virus from spreading

Common sense measures will help to stop the virus spreading such as:

• Staying at home: Avoid busy places if you have the virus.
• Using self-care methods: Eating well and drinking plenty of fluids will help your body recover more quickly from the infection.
• Eating well and following a healthy lifestyle: People who are otherwise fit and healthy tend to recover much more quickly from illness than those who do not take care of themselves.
• Observing basic hygiene rules: Clean all work surfaces and practice hand hygiene.
• Stay on top of your immunizations: Higher risk populations such as children and those with other health conditions such as asthma are routinely offered vaccines to help boost their immunity against viruses. Sometimes, acute bronchitis develops in a patient with asthma or chronic bronchitis. In these cases, it is caused by a complication of an existing medical condition and is not contagious.

Bronchitis in children

Bronchitis in children¹⁰ may be caused by a viral or bacterial infection, dust, allergens, or environmental irritants. Exposure through contact with a person who has acute bronchitis or placing children in a second-hand smoke environment may increase the likelihood of them developing the illness.

Some children may be at a higher risk of developing acute bronchitis if they have chronic sinusitis, allergies, asthma or enlarged adenoids or tonsils.

Symptoms of bronchitis in children include:

• A dry or mucus-filled cough
• A runny or stuffy nose
• Feeling run-down or tired
• Vomiting or gagging
• Sore chest and back from prolonged periods of coughing
• Lethargy- not able to move around as much
• Headaches, fever, and chills
• A tight feeling in the chest
• A sore throat

Symptoms may last for 2–4 weeks.

Bronchitis in children may easily be mistaken for other conditions. Do make sure that you take your child to see a provider for a proper diagnosis so that they can conduct a physical examination and check your child’s medical history. If necessary, they will order other tests to rule out pneumonia, asthma, or other medical conditions.

If you have any concerns about their health, do not delay in seeking advice from a medical practitioner.