Bronchiolitis vs. Bronchitis: How to Differentiate and Treat Symptoms

Bronchiolitis and bronchitis are both infections that affect the lungs and can have overlapping symptoms such as a cough, wheezing, and low-grade fever. However, there are some very important differences in symptoms, causes, treatment, and ultimately, how they may affect future lung function.

Bronchiolitis is an inflammation of the small airways (bronchioles) and most often affects infants less than 2 years of age. Bronchitis causes inflammation of the bronchi (and bronchioles to a degree) and can affect people of any age.

baby at the doctor

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Causes and Symptoms

Symptoms common to both bronchiolitis and bronchitis include:

  • A cough that can be dry, or productive of clear, yellow, or green phlegm
  • Wheezing
  • A low-grade fever
  • A runny or stuffy nose

With both conditions, the cough and wheezing may last for several weeks. Both are often caused by viral infections, but the particular viruses responsible frequently differ.


The symptoms of bronchiolitis can differ from bronchitis both in how the infection affects the respiratory system and based on the age groups in which the infections are found.

Since bronchiolitis often occurs in young children who can’t express how they are feeling, objective signs that parents can visualize are often key in diagnosis.

Symptoms specific to bronchiolitis include:

  • Often begins with upper respiratory symptoms (nasal congestion, etc.)
  • Progresses to the lower respiratory tract after several days
  • In addition to a cough, respiratory rate may be increased (see below).
  • Wheezing (especially with expiration)
  • Children may show signs of breathing difficulty through nasal flaring, grunting, and the use of accessory muscles to breathe (muscles in the neck contract with inhalation).
  • Very young children may have episodes where they stop breathing for moments (apnea).
  • A fever is usually only present early on in the infection and is usually less than 100 degrees F.

A hallmark of bronchiolitis that is not seen with bronchitis is the minute-to-minute variation in symptoms. One moment a child may be sleeping comfortably, the next they may be agitated and appear quite ill, and then they may appear comfortable again after coughing and clearing mucus from their airways.

How Long Do Bronchiolitis Symptoms Last?

Altogether, symptoms last around two weeks, although coughing and wheezing sometimes last longer.

Other symptoms may include:

  • Decreased nursing or eating
  • A decrease in the number of wet diapers
  • Decreased level of playfulness/alertness

An elevated respiratory rate is an important sign and has been coined the neglected vital sign. Respiratory rates run higher in children than adults, with normal respiratory rates in children being:

  • Newborn: 30–60 breaths per minute
  • Infant (1 to 12 months): 30–60 breaths per minute
  • Toddler (1–2 years): 24–40 breaths per minute
  • Preschooler (3–5 years): 22–34 breaths per minute
  • School-age child (6–12 years): 18–30 breaths per minute
  • Adolescent (13–17 years): 12–16 breaths per minute

The most common cause of bronchiolitis is the respiratory syncytial virus (RSV), which has been found to account for roughly 80% of cases. Less commonly, bronchiolitis may also be caused by cold viruses (such as rhinovirus, adenovirus, or coronaviruses), metapneumovirus, human bocavirus, influenza A or B, and parainfluenza.


It’s important to briefly make a distinction between acute bronchitis and chronic bronchitis:

  • Acute bronchitis is the type of bronchitis many people are familiar with that occurs following an upper respiratory infection.
  • Chronic bronchitis is a form of chronic obstructive pulmonary disease (COPD) and is marked by a persistent cough (lasting more than three months) which is often productive of large amounts of phlegm.

Symptoms of acute bronchitis that are less likely to be seen with bronchiolitis include:

Most cases of bronchitis are due to a viral infection, with the most common being:

Bacteria are the cause of only 1% to 10% of cases. Less commonly, atypical bacteria such as mycoplasma, chlamydia, and Bordatella pertussis (the cause of whooping cough) are involved. Non-infectious bronchitis may also occur due to exposure to irritants such as smoke or dust.

  • Children, usually less than 2 years old

  • Symptoms can vary from minute to minute

  • Difficulty breathing may appear as chest retractions, nasal flaring, grunting, use of accessory muscles

  • Decreased nursing/eating, decreased playfulness

  • Any age (uncommon less than age 2)

  • Symptoms either gradually improve or worsen

  • A person may state they feel short of breath

  • Fatigue

At-Risk Groups

Some people are more likely to develop bronchiolitis or bronchitis than others. In general, young children, especially those less than 2 years of age, are more likely to develop bronchiolitis, whereas bronchitis may occur in any age group (although it is uncommon before the age of 2).

Risk Factors for Bronchiolitis

A number of circumstances and conditions increase the chance that a child will develop bronchiolitis, and for those who develop the disease, separate factors increase the risk that it will be serious.

The risk of developing the disease primarily relates to the chance of being exposed to the causative viruses, whereas the chance that a child will become seriously ill is linked more with underlying medical conditions.

Risk factors for developing bronchiolitis include:

  • Age less than 2, with the peak age being from 3 to 6 months
  • The risk of bronchiolitis is highest from late October to early April in the northern hemisphere, with the peak incidence occurring in January (the prevalence can vary year to year). Children who are born such that they reach the peak age (3 to 6 months) in early to mid-winter have the greatest risk.
  • Secondhand smoke exposure
  • Premature delivery
  • Increased exposure to viruses (daycare setting, more siblings, multigenerational families)
  • Having a mother with asthma
  • Congenital heart or lung disease

Factors that increase the chance that bronchiolitis will be serious include:

  • Age less than 12 weeks
  • Boys appear to be at a somewhat greater risk for severe disease than girls
  • Secondhand smoke exposure
  • History of prematurity (especially babies born prior to 32 weeks gestation)
  • Underlying heart disease, lung disease, or neuromuscular disorders
  • Immunodeficiency disorders and other forms of immunosuppression

Risk Factors for Bronchitis

Like bronchiolitis, there are factors that increase the chance a person will develop the condition, as well as factors that may make developing the disease more serious.

Risk factors for developing bronchitis include:

Among those who develop bronchitis, some people are more likely to become seriously ill—for example, developing secondary complications such as pneumonia. This includes:

  • Pregnant people
  • Those who have underlying lung diseases
  • Those who are immunosuppressed (whether due to medications, cancer, or other causes)


There are no formal treatments available for either uncomplicated bronchiolitis or bronchitis (except in uncommon cases when bronchitis is bacterial). The infection generally needs to “run its course.”

If the infection is due to influenza A and diagnosed shortly after the onset of symptoms, some healthcare providers may recommend Tamiflu (oseltamivir). That said, measures can be taken to manage the symptoms and in some cases may reduce the chance that the infection will become more serious.

Both bronchiolitis and bronchitis last, on average, around two weeks. However, a cough or wheezing may persist for some people, even beyond three weeks.

Some treatments that may be recommended for bronchitis are not recommended for bronchiolitis—for example, bronchodilators—so we will discuss these separately.


For a fever or appearance of discomfort, Tylenol (acetaminophen) may be used for most children. Aspirin should not be used in children due to the risk of Reye’s syndrome.

Saline nose drops (and a suction bulb if necessary) may help relieve some congestion.

Roughly 3% of children who develop bronchiolitis end up being hospitalized, and bronchiolitis remains the most common reason for hospital admission in the first 12 months of life.

Inpatient treatment may include:

  • Intravenous fluids (if the child is dehydrated)
  • Oxygen (if oxygen saturation drops below 90%)

Nebulized hypertonic saline may help with airway swelling in infants.

According to clinical practice guidelines, medications such as albuterol (and similar medications), epinephrine, and corticosteroids should not be used. Antibiotics are recommended only if there is clear evidence of a secondary bacterial infection present. When very severe, mechanical ventilation may be needed.

As far as the prevention of RSV, Synagis (palivizumab) is a monoclonal antibody that helps prevent severe lower respiratory tract illnesses in premature babies and children 2 years old and younger who are at high risk of serious complications from RSV. It's a shot given once a month during RSV season.


For fever or discomfort, Tylenol (acetaminophen) is usually recommended. Resting, including taking a nap during the day if needed, can’t be understated. If you have a difficult time giving yourself permission to rest, imagine your body needing the energy to fight off the virus and heal your airways.

Should You Take Cough Medicine?

Some people find cough medications or an expectorant helpful, but a 2021 study confirmed earlier findings and found that a spoonful of honey was actually more helpful than common cold and cough medications. Honey is not recommended for children less than 1 year old.

Other treatments will depend on how symptoms progress. For example, if a secondary bacterial infection should develop, antibiotics may be necessary. Some people develop reactive airway disease with bronchitis, and treatments such as an albuterol inhaler to open the airways or corticosteroids to reduce inflammation may be needed.


Both bronchiolitis and bronchitis may lead to complications, though the particular complications and when they might occur vary between the conditions.


With bronchiolitis, low oxygen levels (hypoxia) requiring oxygen supplementation may occur and require hospitalization. Dehydration may also occur and can be treated with IV fluids.

With severe disease, respiratory failure may sometimes occur, requiring mechanical ventilation and sedation. Bacterial co-infections, such as ear infections (otitis media) and urinary tract infections, have also been seen.

A number of studies have evaluated the possible association of bronchiolitis early in life with wheezing and childhood asthma later on, with mixed results. When asthma is seen later in childhood, it’s also not known whether having bronchiolitis may damage the lungs in a way that would predispose to asthma, or if instead a child’s particular immune response or lung function might predispose them to develop both bronchiolitis and recurrent wheezing.

Wheezing Later in Childhood

A 2021 review looking at 22 studies found that lower respiratory tract infections (such as bronchiolitis) in children less than 3 years of age were associated with an increased risk of the subsequent development of wheezing later in childhood. The risk was roughly three times higher than for those who did not have these infections.


One of the most common complications of bronchitis is a secondary pneumonia which is most commonly bacterial.

Potentially worrisome symptoms are listed below and frequently present in younger people who go on to develop pneumonia. In people over the age of 75, however, symptoms of pneumonia may be more subtle, and it’s important to contact your healthcare provider with any concerns or if symptoms persist.

When to Call the Healthcare Provider

Both bronchiolitis and bronchitis most often resolve on their own, but it’s important to be aware of symptoms that could suggest complications and when to call your healthcare provider.


Signs of concern with bronchiolitis may include:

  • Signs of breathing difficulty such as nasal flaring, clenching of neck muscles while breathing, retraction of chest muscles with breathing, or grunting
  • An elevated respiratory rate
  • Difficulty or loss of desire to nurse/eat
  • Decreased urination (fewer wet diapers)
  • Cyanosis (a bluish tinge to lips or fingers)
  • A temperature greater than 100 degrees F
  • Decreased level of alertness
  • Symptoms such as a cough that persists beyond two to three weeks


Signs to call your healthcare provider with bronchitis include:

  • Symptoms that persist beyond two to three weeks
  • Significant wheezing, or wheezing that occurs with both exhalation and inhalation
  • A temperature greater than 100 degrees F
  • Shortness of breath
  • Chest pain (other than the achiness associated with coughing)
  • Mucus that is blood tinged or rust colored
  • Mucus that is foul smelling
  • A pulse rate greater than 100
  • A respiratory rate higher than 24 breaths per minute (at rest)
  • In the elderly, confusion or excessive tiredness

A Word From Verywell

Both bronchitis and bronchiolitis are lower respiratory infections that usually run their course without problems. That said, it’s important to be aware of potential complications as well as when you should call your healthcare provider.

Since bronchiolitis often occurs in young infants, it can be very frightening for parents. Make sure to call your healthcare provider with any concerns, even if you suspect everything is OK. And trust your gut. Your instinct as a parent is often the best “diagnostic test” available.

10 Sources
Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
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Additional Reading

By Lynne Eldridge, MD
 Lynne Eldrige, MD, is a lung cancer physician, patient advocate, and award-winning author of "Avoiding Cancer One Day at a Time."