What Is Bronchiolitis?


Bronchiolitis is an inflammation of the lungs' small airways. It's an acute viral infection that causes swelling and mucus buildup in the smaller airways in the lungs, which are about 2mm diameter or less in size and are also known as bronchioles.

People who have this infection have fatigue and breathing problems due to swelling or blockage. In worst-case scenarios, it might cause the lungs to collapse. Although bronchiolitis is a common infection in children, it can occasionally afflict adults as well.

To discover more about the causes, symptoms, signs, management, and treatments, keep reading. Also, this article offers useful advice on how to diagnose and prevent this condition.

Causes of bronchitis 

Although bronchiolitis is typically mild, it can occasionally be severe. It is a seasonal illness that is more common during the winter months in some places and the rainy season in others.

Before turning one year old, bronchiolitis affects 11% to 15% of children. In addition, 5 out of 1000 kids under the age of 2 who have bronchiolitis are hospitalized.

The following have been found to cause bronchiolitis:

  1. Human Bocavirus(HBOV)

According to studies, the Human Bocavirus (HBOV) was initially identified in patients with gastroenteritis and respiratory tract infections in 2005.3 This virus is a member of the parvoviridae virus family that usually affects vertebrates including humans. Human bocavirus-induced bronchiolitis can cause severe bronchiolitis symptoms in immunocompromised individuals, and in extreme situations, it can be fatal. Coughing, a runny nose, and shortness of breath are symptoms of this virus.

  1. Human Metapneumovirus 

This virus belongs to the Paramyxovirus family. It has symptoms that are similar to those of the common cold, but in persons with compromised immune systems, it may be more severe. Through intimate contact and touching of contaminated objects or surfaces, it spreads quickly from person to person. The lower and upper respiratory systems are both impacted by the virus.

Because of a weakened immune system, persons over 65 years, those under the age of 5, those with chronic obstructive pulmonary disease (COPD), and children under the age of five are more vulnerable to this virus. Sneezing, coughing, fever, shortness of breath, or a runny nose are some of the symptoms of this virus.

  1. Rhinovirus 

The most prevalent cause of colds is this virus, which was originally identified in 1956.2 The lower respiratory tract may also be affected, however, they mostly target URTIs (upper respiratory tract infections). Rhinovirus affects most children with about 8-10 colds during their first 2 years of life. This virus is transmitted to the upper respiratory tract by airborne droplets. Moreover, a rhinovirus may make you feel fatigued or give you a sore throat or runny nose.

  1. Parainfluenza Virus type 3 

Many respiratory disorders are caused by this virus. It belongs to the family of widespread viruses called human parainfluenza viruses (HPIV). Pneumonia and bronchiolitis are linked to parainfluenza virus 3. Children, those over 65 years, and those with weakened immune systems are most vulnerable to the severe bronchiolitis disease caused by this virus. Fever, cough, runny nose, exhaustion, or sore throat are all symptoms of this virus.

This virus can spread if you come into contact with an infected person, touch a contaminated surface or item, or remain close to someone infected and sneeze or cough into the air.

  1. Adenovirus 

The symptoms of this infection resemble those of the cold or the flu. It can affect kids of any age and affects the lining of the lungs, intestine, eyes, and airways. Nasal congestion, coughing, fatigue, fever, or muscle soreness are all signs of this virus. By the time they turn 10 years old, most kids have at least one type of adenovirus infection. The following scenarios present a risk of spreading this virus to your child: 

  • Through sneezing or coughing in the air
  • Touching objects or surfaces with the virus and then touching your face, mouth, nose, and eyes
  • Infected water or untreated water( like in swimming pools)
  • Through faeces
  1. Respiratory Syncytial Virus(RSV infection)

This virus commonly affects the respiratory system and produces mild cold-like symptoms. Healthy people might have mild symptoms, but it could be severe in infants and the elderly with compromised immune systems. The respiratory syncytial virus is one of the common causes of bronchiolitis(inflammation) of the lungs. The respiratory syncytial virus infection appears 4-6 days after exposure to the virus. Some of the symptoms of this virus include headache, sore throat, sneezing, wheezing, running nose, decreased appetite, and headache.

Signs and symptoms of bronchiolitis 

According to Asthma and lung Uk, bronchiolitis usually starts like a common cold.8 It could either be mild symptoms or severe depending on if you are healthy or you are immunocompromised. 

Mild symptoms

  1. Running nose
  2. Dry cough3
  3. Stuffy nose
  4. Wheezing
  5. Difficulty swallowing food or liquid

Severe symptoms 

Over the next several days, your child may experience the following symptoms:

  1. Loss of appetite
  2. Hypoxemia- low levels of oxygen in the blood
  3. Blue discoloration of the skin or lips
  4. Rapid breathing
  5. Fever
  6. Becoming sluggish
  7. Intercostal retraction- this is when the muscles between your child's ribs go inwards due to reduced pressure in the chest
  8. Dehydration from a reduction in oral intake and vomiting

According to the National health service, symptoms generally get worse between 3 and 5 days and coughs get better in 3 weeks.

Management and treatment for bronchiolitis 

According to Asthma and Lungs Uk, 3 out of every 100 cases may require hospitalization if symptoms worsen. Hospital treatments include the following:

  1. Nasal Suction 

Your healthcare provider may insert a plastic tube in your child's nostrils to remove mucus that is obstructing the airways if it's blocked or having breathing difficulty. 

  1. High-flow nasal cannula therapy 

This ventilatory support is used for children with bronchiolitis in intensive care. To enable appropriate breathing involves delivering a high flow of oxygen to the affected child's respiratory system.

  1. Nasogastric feeding 

Another name for this treatment is called NG feeding. It is a surgical operation that involves inserting a tube via the nose, food pipe , and stomach. A child who has a lot of difficulties swallowing food can get nutrition through this method. An infected child is given nourishment and assistance by having a tube that delivers a nutrient-rich fluid straight to the stomach.

  1. Nebulizer therapy 

This involves using a nebulizer to help your child breathe in medicine to open their airways or treat the infection. One medication that patients receiving nebulizer therapy can receive is saline solution.4 As your child's airways are obstructed and they have trouble breathing, saline water helps to cleanse the respiratory passageway.

  1. Palivizumab injection 

Your healthcare provider may give your child a palivizumab injection to prevent serious lung infections in babies caused by a respiratory syncytial virus(RSV). It is a medication that strengthens your child's antibodies against illness and guards them against RSV infection.


How is bronchiolitis diagnosed 

When you take your child to the doctor, they typically ask questions such as, "When did the condition start? Which drugs have you used? Has the child had a fever or been around an infected individual?”

Your healthcare provider will ask you these crucial questions before performing a physical examination, which involves carefully examining your child's lungs with a stethoscope placed on their back. Also, your child's blood oxygen saturation levels are checked and measured using an oximeter that is placed on your child's finger or toe.

Depending on the severity of symptoms, other clinical diagnoses may be made in addition to the physical examination that may be performed. Your healthcare provider might make one of the following diagnoses:

  1. CT scan or chest X-ray- for imaging of the whole chest and to ascertain the health of your child's lungs
  2. Nasal swab- samples are taken from your child's upper throat or nostrils to examine sample cells to determine infection of the respiratory system
  3. Rapid RSV antigen Test- it's a test conducted to collect fluid in the nostrils to check for the respiratory syncytial virus(RSV)
  4. Nasal Aspirate or wash- this test involves the insertion of saline solution into your child's nose and removing it with suction. This is done to collect RSV infection
  5. Spirometry- it's used to ascertain how much air your child inhales, exhales, and how quickly they exhale.  It's also used to check for conditions that affect breathing
  6. Blood test- to check white blood cell count and any sign of infection in the body
  7. Blood culture test- it's a test carried out to check for viruses or bacteria in the blood
  8. Arterial blood gas analysis(ABG)- this diagnosis requires a blood sample to measure and provide information about the amount of oxygen, and carbon dioxide in your blood, and the acidity of your child's blood

How can I prevent bronchiolitis 

Since symptoms frequently improve on their own, there is no precise strategy or treatment. By doing the following, you can protect your child from contracting bronchiolitis:

  1. Wash your child's hands frequently
  2. Keep your child away from cigarette smoke or any other smoke
  3. Clean surfaces and wash your child's toys with disinfectant
  4. Use saline nasal drops to keep your child's nostrils clear. Ensure to follow your healthcare provider when using it
  5. Should your child get infected, you can use a suction bulb to clear your child's airways, it will help your child breathe well
  6. Ensure your child sits upright to enable proper breathing

Who are at risk of bronchiolitis 

Bronchiolitis is most common in young children below 2 years of age. The following are the people at risk of bronchiolitis: 

  1. Children whose immune systems have been compromised
  2. Babies born prematurely
  3. Children with heart or lung conditions
  4. Children that are not breastfed
  5. Children exposed to dangerous chemicals and cigarette smoke
  6. Children that get close to other infected children or persons
  7. Living in a crowded house with a heating stove
  8. Having autoimmune connective tissue disease

What’s the difference between bronchiolitis and bronchitis 

Both bronchiolitis and bronchitis are infections that affect the lungs. While bronchitis affects the larger airways(trachea and upper bronchial tubes), bronchiolitis affects the small airways(bronchioles). 

While bronchiolitis typically affects infants or young children under the age of 2, bronchitis typically affects older children and adults.

When should I see a doctor 

Normally, symptoms of bronchiolitis usually last for a couple of weeks but you can call your healthcare provider if your child starts to exhibit any of the symptoms listed below:

  1. Cough that doesn't go away 
  2. Fever or common cold that suddenly worsens
  3. Breathing fast or incoherently
  4. Lips, tongue, or skin turning blue or pale
  5. Having breathing Difficulty
  6. Becomes fatigued 
  7. Starts to show signs of dehydration 
  8. Becomes sluggish 
  9. The muscle under the ribs becomes visible
  10. Nasal flaring while breathing


Bronchiolitis is a seasonal disease that primarily affects young children under the age of two. It attacks the lungs' small airways, causing inflammation and the inability to breathe normally. This infection usually clears up in a few weeks, but it can worsen over time. A respiratory syncytial virus is commonly responsible for this illness. This respiratory problem can be managed physically or clinically as explained in this article.

When a child exhibits severe bronchiolitis symptoms for an extended period, parents are advised to take the affected child to the clinic. They should be prepared to answer some vital questions from your healthcare provider. The answer they provide arms your healthcare provider with a good idea and a head start on how to diagnose the infection.

To prevent bronchiolitis, you must clean surfaces and toys with disinfectant and keep your child away from other infected babies. When your child sneezes or coughs, cover their mouth and nose with tissue paper. Tissue paper should be discarded immediately after use.


  1. Rikhotso MC, Kabue JP, Ledwaba SE, Traoré AN, Potgieter N. Prevalence of human bocavirus in africa and other developing countries between 2005 and 2016: a potential emerging viral pathogen for diarrhea. Journal of Tropical Medicine [Internet]. 2018 Sep 12 [cited 2023 Mar 3];2018:e7875482. Available from: https://www.hindawi.com/journals/jtm/2018/7875482/
  2. Kennedy JL, Turner RB, Braciale T, Heymann PW, Borish L. Pathogenesis of rhinovirus infection. Curr Opin Virol [Internet]. 2012 Jun [cited 2023 Mar 3];2(3):287–93. Available from: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3378761/
  3. Mahashur A. Chronic dry cough: Diagnostic and management approaches. Lung India [Internet]. 2015 [cited 2023 Mar 3];32(1):44–9. Available from: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4298918/
  4. BARSKI P, SURDACKI M, SAJ A, WRÓBLEWSKA A, ORNAT M, PAWELAK A, et al. Isotonic saline nebulization and lung function in children with mild respiratory ailments. Physiol Res [Internet]. 2020 Dec 1 [cited 2023 Mar 4];69(Suppl 1):S131–7. Available from: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8604049/
This content is purely informational and isn’t medical guidance. It shouldn’t replace professional medical counsel. Always consult your physician regarding treatment risks and benefits. See our editorial standards for more details.

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Oluwasola Samuel

Bs.c, Economics, Osun state University

Hello, I'm Oluwasola Samuel,a medical writer. Aside from that, I work as an Insurance Sales Associate. My work in the insurance industry has made me more aware of the careless and dismissive attitudes that some people have toward health issues.
As a health advocate and writer, I use thoroughly researched data to help my audience make informed health decisions that will enhance their quality of life.
I am creative and have strong research, communication, time management, and qualitative abilities. All of these assist me in creating excellent health content that not only connects with my audience but also captivates them and establishes effective communication.

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