Bronchiolitis

Overview

Bronchiolitis is a common lung infection in babies and young children. It affects the small airways in the lungs, called bronchioles. When these airways become inflamed and filled with mucus, breathing can become more difficult. Bronchiolitis is most often seen in infants under 2 years of age, especially during colder months, although it can occur at any time of year.

Most children with bronchiolitis have a mild illness and recover with supportive care. However, some babies, particularly very young infants or those with certain medical conditions, may need medical assessment or hospital care. Because symptoms can change quickly in young children, parents and caregivers should monitor breathing, feeding, and hydration closely.

Symptoms

Bronchiolitis often begins like a common cold. Early symptoms may include a runny or blocked nose, mild cough, and sometimes a low-grade fever. Over the next few days, the infection may move into the lower airways and cause breathing-related symptoms.

• Cough that may become more frequent
• Fast or noisy breathing
• Wheezing, which is a whistling sound when breathing out
• Difficulty feeding due to breathing effort or tiredness
• Irritability or unusual sleepiness
• Fewer wet diapers than usual, which may suggest dehydration
• Pauses in breathing, especially in very young infants

Some children may show signs of increased work of breathing, such as the skin pulling in between the ribs, flaring of the nostrils, or grunting. These signs need prompt medical attention.

Causes and Risk Factors

Bronchiolitis is usually caused by a virus. The viruses that cause colds and respiratory infections can spread through droplets from coughing or sneezing, close contact with infected people, or touching contaminated surfaces and then touching the face.

Children are more likely to develop bronchiolitis because their airways are small and can become blocked more easily by swelling and mucus. Certain factors can increase the chance of more severe illness:

• Age under 3 months
• Premature birth
• Underlying heart or lung disease
• Weakened immune system
• Exposure to tobacco smoke
• Close contact with other young children, such as in childcare settings
• Not being breastfed, in some cases, as breast milk can provide immune support

Bronchiolitis is contagious, particularly in the early days of illness. Good hand hygiene, avoiding close contact with sick individuals, and keeping children away from smoke can help reduce risk.

Diagnosis

A doctor usually diagnoses bronchiolitis based on the child’s age, symptoms, medical history, and a physical examination. During the examination, the doctor may listen to the child’s chest, assess breathing effort, check temperature, and evaluate hydration.

In many cases, additional tests are not needed. If symptoms are severe, unusual, or if another condition is suspected, the doctor may consider further evaluation. This may include measuring oxygen levels with a small sensor, laboratory testing for respiratory viruses, or imaging if there is concern about another lung problem. The decision depends on the child’s condition and clinical findings.

Bronchiolitis can sometimes resemble other illnesses, such as asthma-like wheezing, pneumonia, or upper airway infections. Medical assessment helps determine the most appropriate care and whether monitoring is needed.

Treatment Options

Treatment for bronchiolitis is mainly supportive, meaning care focuses on helping the child breathe comfortably, stay hydrated, and recover while the infection runs its course. Antibiotics are not used for typical viral bronchiolitis unless there is a separate bacterial infection suspected by a doctor.

For mild cases, care may include ensuring adequate fluids, helping keep the nose clear, and monitoring breathing and feeding. Parents should follow the advice of their child’s healthcare provider, especially for very young infants or children with existing medical conditions.

Some children may need hospital care if they have low oxygen levels, dehydration, significant breathing difficulty, or pauses in breathing. In hospital, treatment may include oxygen support, fluids if feeding is not sufficient, and close monitoring. The level of support depends on the child’s needs.

Not all breathing treatments are helpful for bronchiolitis, and their use varies depending on the child’s symptoms and medical assessment. A healthcare professional will decide whether any additional treatment is appropriate.

Recovery can take time. Breathing symptoms often improve gradually, while cough may last longer. Parents should seek medical guidance if symptoms worsen or if they are unsure about their child’s condition.

When to See a Doctor

Parents and caregivers should contact a doctor if a baby or young child has signs of bronchiolitis, especially if the child is very young, was born prematurely, or has heart, lung, or immune system problems.

Seek urgent medical care if any of the following occur:

• Difficulty breathing, fast breathing, or severe chest pulling
• Bluish color around the lips or face
• Pauses in breathing
• Unable to feed or significantly reduced feeding
• Signs of dehydration, such as very few wet diapers, dry mouth, or unusual drowsiness
• Extreme tiredness, limpness, or difficulty waking
• Fever in a very young infant
• Symptoms that worsen after initially seeming mild

Bronchiolitis can be worrying for families, but many children recover with appropriate monitoring and supportive care. Early medical advice is important when breathing, feeding, or hydration is affected.