Bronchiolitis: Signs, Causes, and How to Help Your Child
A guide for parents on bronchiolitis. Learn to identify the signs, understand the causes, and discover effective ways to care for your child at home and when to seek medical help.
Written by Dr. Shaik Abdul Kalam
Reviewed by Dr. D Bhanu Prakash MBBS, AFIH, Advanced certificate in critical care medicine, Fellowship in critical care medicine
Last updated on 17th Sep, 2025
Introduction
Hearing your baby cough, wheeze, and struggle to breathe is a terrifying experience for any parent. Often, these distressing symptoms point to a common but serious lung infection called bronchiolitis. Primarily affecting infants and young children, this condition causes inflammation and mucus buildup in the smallest airways of the lungs (the bronchioles), making it difficult to breathe. While most cases are mild and can be managed at home, some can escalate quickly, requiring medical attention. This comprehensive guide will walk you through everything you need to know: what causes bronchiolitis, how to spot the early and dangerous signs, effective home care strategies, and crucially, when it's time to call a doctor. Our goal is to empower you with knowledge and calm your fears, ensuring you can provide the best care for your little one.
What Exactly is Bronchiolitis?
Bronchiolitis is a common respiratory infection that affects the bronchioles. To understand it, imagine the lungs as an upside-down tree. The windpipe is the trunk, which branches into larger airways called bronchi. These bronchi then split into smaller and smaller branches, and the very smallest are the bronchioles. When a virus infects these tiny tubes, they become swollen, inflamed, and filled with mucus. This blockage makes it hard for air to flow freely in and out of the lungs, leading to the characteristic wheezing and difficulty breathing seen in bronchiolitis.
It is most prevalent in children under the age of 2, with the peak incidence occurring between 3 and 6 months of age. Almost all children will have been infected by the virus that causes it by the time they are 2 years old, but only a fraction will develop the full-blown illness.
Bronchiolitis vs. Bronchitis: What's the Difference?
People often confuse these two terms. The key difference lies in the location of the infection.
Bronchitis affects the larger, central airways (the bronchi) and is more common in adults and older children. It often presents with a persistent, productive cough.
Bronchiolitis affects the smaller, deeper airways (the bronchioles) and is almost exclusively an illness of babies and toddlers. Its hallmark is breathing difficulty and wheezing.
Consult Top Specialists
The Primary Cause: The Respiratory Syncytial Virus (RSV)
The overwhelming majority of bronchiolitis cases—up to 80%—are caused by the Respiratory Syncytial Virus, or RSV. This highly contagious virus is so common that it circulates in predictable seasonal outbreaks, typically from fall to early spring. Almost all children get an RSV infection by their second birthday. For most, it causes nothing more than a simple cold. But for infants, especially those born prematurely or with underlying heart or lung conditions, RSV can descend into the lungs and cause bronchiolitis.
Other Viruses That Can Lead to Bronchiolitis
While RSV is the main culprit, other viruses can also cause the same illness. These include:
Rhinovirus (the common cold virus)
Influenza (the flu virus)
Human metapneumovirus
Adenovirus
Parainfluenza virus
Recognizing the Signs and Symptoms of Bronchiolitis
The illness typically follows a predictable pattern, starting like a cold and potentially progressing to more severe respiratory symptoms over a few days.
Early Symptoms: The First Few Days
The first 1-3 days often look identical to a common cold:
Runny or stuffy nose
Mild cough
Sometimes a slight fever (less than 101°F or 38.3°C)
Fussiness or decreased appetite
Progressing Symptoms: When to Be More Concerned
As the infection moves into the lungs, you may notice signs of respiratory distress over the next 2-4 days:
Wheezing: A whistling or musical sound when your baby breathes out.
Rapid or labored breathing: Your baby's chest may seem to suck in between the ribs or under the ribcage with each breath (a sign called "retractions").
Rapid heartbeat.
Worsening cough: The cough may become more persistent and sound tighter.
Difficulty feeding: The baby may struggle to breathe and suck at the same time, leading to shorter feeds and risk of dehydration.
Symptoms of Severe Bronchiolitis Requiring Emergency Care
Grunting: A grunting sound with each breath.
Nasal flaring: The nostrils widen dramatically with each breath.
Cyanosis: A bluish or gray color to the skin, especially around the lips and fingernails, indicating a lack of oxygen.
Apnea: Pauses in breathing for more than 10-15 seconds.
Severe lethargy or difficulty waking up.
Signs of dehydration: Fewer wet diapers (less than 1 every 6-8 hours), no tears when crying, sunken soft spot on the head.
Unique Insight: Many parents monitor fever as the main sign of severity, but with bronchiolitis, work of breathing is a far more critical indicator. A baby with a mild fever who is breathing easily is often less concerning than a baby with no fever who is working hard to breathe.
How is Bronchiolitis Diagnosed?
The Role of a Physical Exam
In most cases, a doctor can diagnose bronchiolitis based on:
The history of symptoms you provide.
A physical examination: The doctor will listen to your child's lungs with a stethoscope to check for wheezing and crackles, observe their breathing rate and effort, and check their oxygen saturation levels with a pulse oximeter—a painless clip placed on a finger or toe.
When are Lab Tests Needed?
Typically, no tests are needed for a clear-cut case. However, if the illness is severe or the diagnosis is uncertain, the doctor may order:
A nasal swab test to identify the specific virus (e.g., RSV, flu).
A chest X-ray to check for signs of pneumonia or rule out other causes of breathing difficulty.
Blood tests to check for signs of dehydration or elevated white blood cells.
If a diagnosis is needed quickly, you can consult a pediatrician online with Apollo24|7 for an initial assessment and to determine if an in-person visit is necessary.
Treating Bronchiolitis: Focus on Supportive Care
Since bronchiolitis is caused by a virus, antibiotics are ineffective. The mainstay of treatment for bronchiolitis is supportive care—helping your child breathe more comfortably and stay hydrated while their immune system fights off the virus.
Effective Home Remedies and Comfort Measures
Hydration is Key: Offer frequent, small amounts of breast milk, formula, or an electrolyte solution like Pedialyte.
Saline Drops and Suction: Use over-the-counter saline nasal drops to loosen mucus, followed by gentle suction with a bulb syringe or nasal aspirator before feeds and naps.
Cool-Mist Humidifier: Running a humidifier in the baby's room can moisten the air and ease coughing and breathing.
Keep Air Clean: Avoid exposure to tobacco smoke or other irritants.
Comfort and Rest: Hold your baby upright, which can make breathing easier than when they are lying flat.
What to Avoid: Medications Not Recommended for Infants?
Do not give over-the-counter cough and cold medicines to infants and young children, as they can have serious side effects and are not proven to help.
Avoid aspirin due to the risk of Reye's syndrome.
Medical Treatments for Severe Cases
For severe bronchiolitis requiring hospitalization, treatment may include:
Supplemental oxygen to ensure blood oxygen levels remain safe.
IV fluids to correct or prevent dehydration.
Nebulized hypertonic saline to help loosen mucus in the airways.
In very rare, extreme cases, mechanical ventilation may be needed to help the baby breathe.
How Long Does Bronchiolitis Last? The Typical Timeline
The bronchiolitis recovery time can vary, but a general timeline is:
Days 1-3: Cold-like symptoms appear.
Days 3-5: Respiratory symptoms (cough, wheezing) peak. This is often the most worrisome period.
Day 5 onward: Symptoms gradually begin to improve.
The lingering cough can often last for 2 to 4 weeks, even after the other symptoms have resolved. The wheezing typically disappears much sooner.
Preventing Bronchiolitis: Key Strategies for Parents
Prevention is the best medicine, especially for bronchiolitis in infants.
The Importance of Hand Hygiene
Frequent hand washing with soap and water for at least 20 seconds is the single most effective way to prevent the spread of viruses.
Limiting Exposure to Sick Individuals
Keep infants away from anyone with cold symptoms.
Avoid crowded places during peak RSV season.
Practice good cough etiquette (coughing into your elbow).
Understanding Palivizumab (Synagis) for High-Risk Infants
This is not a vaccine but a monthly injection of antibodies given during RSV season to protect certain high-risk infants (e.g., those born very prematurely or with significant heart or lung disease). A doctor must determine if a child qualifies.
When to Definitely Call a Doctor or Seek Emergency Care?
Seek immediate medical attention if your child shows any of the following "red flag" symptoms:
Struggling to breathe or pauses in breathing.
Lips, tongue, or skin turning blue or gray.
Severe dehydration (no wet diaper for 8+ hours, no tears, sunken eyes).
Extreme lethargy or difficulty waking.
A high fever in a child under 3 months old.
If you are unsure about your child's symptoms or if their condition does not improve after trying supportive measures, book a physical visit to a doctor with Apollo24|7 for a thorough evaluation.
Quick Takeaways: Key Points on Bronchiolitis
Bronchiolitis is a common viral lung infection in infants, primarily caused by RSV.
It starts like a cold but can progress to cause wheezing and breathing difficulties.
There is no specific cure; treatment focuses on supportive care at home.
Monitor your child's breathing effort more closely than their fever.
Keep your child hydrated and use saline drops/suction to clear nasal mucus.
Avoid cough and cold medicines in young children.
Know the "red flag" symptoms that require immediate emergency care.
Conclusion
Navigating a bronchiolitis diagnosis for your child can be a stressful and exhausting experience. Remember, you are not alone. By understanding the causes, recognizing the signs early, and implementing simple, effective comfort measures, you can provide immense relief to your little one. Trust your instincts as a parent—you know your child best. If their breathing becomes labored, they show signs of dehydration, or you simply feel that something is wrong, do not hesitate to seek professional medical advice. While the cough may linger, the vast majority of children recover from bronchiolitis fully without any long-term complications. Your calm presence and attentive care are the most powerful medicines your child can receive during their recovery.
Consult Top Specialists
Consult Top Specialists
Dr. Anila Vishwanath
Ent Specialist
17 Years • MBBS,MS (Oto-Rhino-larynology)
Bengaluru
Hospitec multi-speciality hospital, Bengaluru
Dr. Bhethala Sharan Prakash
General Physician/ Internal Medicine Specialist
5 Years • MBBS MD
Bengaluru
PRESTIGE SHANTHINIKETAN - SOCIETY CLINIC, Bengaluru
Dr. Major Bhaskar K
Ent Specialist
30 Years • MBBS,MS ENT (OTO - Rhino-Laryngology)
Bangalore
Apollo Clinic Bellandur, Bangalore
Dr. Aijaz Muzamil
Ent Specialist
46 Years • MBBS, Ms ENT
Bengaluru
Apollo Clinic, Sarjapur Road, Bengaluru
Dr. Safina Kauser
Ent Specialist
7 Years • MBBS, MS
Bengaluru
Apollo Clinic, JP nagar, Bengaluru
Frequently Asked Questions
1. Is bronchiolitis contagious?
Yes, it is highly contagious. The viruses that cause it spread through tiny respiratory droplets when an infected person coughs, sneezes, or talks. The virus can also live on surfaces for several hours.
2. Can adults get bronchiolitis?
It is very rare in healthy adults. When adults contract the viruses that cause it (like RSV), they typically only experience a common cold. However, it can be serious for older adults or those with weakened immune systems or chronic lung conditions.
3. Can my child get bronchiolitis more than once?
Yes, it is possible to get it again. However, subsequent infections are usually less severe than the first one, as the body builds up some immunity.
4. What's the best position for a baby with bronchiolitis to sleep in?
Always place your baby on their back to sleep, as this is the safest position to reduce the risk of SIDS. To help with breathing, you can try allowing them to sleep in a slightly upright position in your arms or a car seat, but they should always be transferred to a flat, firm, back-sleeping surface for unsupervised sleep.
5. Are there any long-term effects of bronchiolitis?
Most children recover completely. However, some studies suggest that severe bronchiolitis can be linked to a higher chance of developing recurrent wheezing or asthma later in childhood. This is an area of ongoing research.