Bronchiolitis: A Comprehensive Guide
Medically reviewed by Andre Stone | MD, University of Pittsburgh School of Medicine on April 1st, 2026.
Published on April 1st, 2026. Updated on August 24th, 2026.
Key Takeaways
Bronchiolitis is a common lung infection that affects babies and young children under 2 years old
It causes inflammation and swelling in the small airways of the lungs called bronchioles
Most cases are mild and can be managed at home with rest and supportive care
Severe cases may require hospitalization, especially in very young babies or those with health conditions
The illness typically peaks in winter months and is most often caused by respiratory syncytial virus (RSV)
Overview
Bronchiolitis is a viral infection that affects the smallest airways in the lungs. These tiny tubes, called bronchioles, become inflamed and filled with mucus. This makes it hard for air to flow in and out of the lungs.
The condition mainly affects children under 2 years old. It's most common in babies under 6 months. Nearly all children are infected with RSV by age 2, but not all of them develop bronchiolitis. Most cases happen during winter months when viruses spread more easily.
While bronchiolitis can be scary for parents, most children recover completely at home. However, some babies may need hospital care if they have trouble breathing or eating. Understanding the signs and symptoms helps parents know when to seek medical care. The viruses that cause bronchiolitis can spread through coughs, sneezes, close contact, and contaminated hands or surfaces. How long a child remains contagious depends on the virus, so continue careful handwashing and follow your healthcare professional's advice. Children can be infected again by viruses such as RSV, even after they have recovered from an earlier infection. Children can have bronchiolitis or similar viral infections more than once, and the severity of a later illness can vary.
Symptoms & Signs
Bronchiolitis symptoms usually start like a common cold. The illness then gets worse over 2-3 days before slowly improving. Symptoms can last 1-2 weeks total.
Primary Symptoms
Runny or stuffy nose - Usually the first sign, often with clear mucus that may turn yellow or green
Cough - Starts dry but may become wet and persistent, often worse at night
Fever - Low-grade temperature, typically under 101°F (38.3°C) in most cases
Difficulty breathing - Fast breathing, wheezing sounds, or working harder to breathe with visible chest retractions
When to Seek Care
Watch for signs that your child needs medical attention. These include breathing faster than normal, working hard to breathe, or refusing to eat or drink. For a baby younger than 3 months, a rectal temperature of 100.4°F (38°C) or higher requires prompt medical evaluation. Seek advice promptly if the baby seems ill even without a measured fever. Some babies make grunting sounds when they breathe or use their belly muscles to help them breathe. If you see your baby's skin pulling in at the ribs or neck when breathing, this means their lungs are working too hard. Call your doctor if your baby seems very tired, sleepy all the time, or doesn't respond normally to you.
When to Seek Immediate Care
Get emergency help if your baby has blue lips or face, severe difficulty breathing, pauses in breathing, or becomes very sleepy and hard to wake up.
Causes & Risk Factors
Age
Risk Factors
Babies under 6 months have the highest risk, especially those under 3 months.
Genetics
A family history of asthma or allergies may be relevant when a clinician evaluates wheezing, but established risks for severe bronchiolitis include very young age, premature birth, and certain heart, lung, or immune conditions.
Lifestyle
Exposure to cigarette smoke significantly increases risk and severity
Other Conditions
Premature birth, heart defects, lung disease, or immune system problems
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Diagnosis
Diagnosis
Medical History & Physical Examination
Your doctor will ask about your child's symptoms and how long they've been sick. They'll want to know about fever, eating habits, and any changes in breathing. The doctor will also ask about exposure to other sick children and any family history of asthma or allergies.
During the physical exam, the doctor will listen to your child's lungs with a stethoscope. They'll check for wheezing, crackling sounds, or areas where air isn't moving well. The doctor will also look at how hard your child is working to breathe and check their oxygen levels.
Diagnostic Testing
Pulse oximetry - A small sensor on the finger or toe measures oxygen levels in the blood
Chest X-ray - Usually not needed for typical bronchiolitis, but a clinician may order one if the diagnosis is unclear or complications are suspected
Nasal swab - A cotton swab in the nose can test for specific viruses like RSV, especially in hospital settings
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Treatment Options
Most children with bronchiolitis get better at home with supportive care. The goal is to help your child feel comfortable while their body fights the infection.
Conservative Treatments
Rest and fluids - Plenty of sleep and small, frequent feedings help the body heal and prevent dehydration
Saline nose drops - Salt water drops can help clear stuffy noses and make breathing easier
Cool mist humidifier - Moist air can help loosen mucus and soothe irritated airways
Fever management - Acetaminophen or ibuprofen (if over 6 months) can reduce fever and discomfort
Advanced Treatments
Oxygen therapy - Extra oxygen through a mask or nasal tube for children with low oxygen levels
IV fluids - Fluids given through a vein when children can't drink enough or become dehydrated
Bronchodilators are not routinely recommended for bronchiolitis because they generally do not improve the illness. A clinician may consider other diagnoses or treatments based on the child's individual examination.
Living with the Condition
Daily Management Strategies
Always place a baby flat on their back on a firm, level sleep surface without pillows, wedges, positioners, or other loose items. If breathing seems too difficult while lying down, seek medical advice. Use a bulb syringe to gently remove mucus from your baby's nose before feeding. Offer smaller, more frequent meals since breathing problems can make eating tiring. Watch for signs that your child is getting worse, such as increased breathing difficulty or refusing to eat.
Patience is important during recovery since some symptoms last longer than others. The cough may continue even after your child starts feeling better and eating normally. Your child might seem frustrated or fussy during this time because they don't feel well. Keep the house quiet and calm to help your baby rest and heal faster. Make sure your child drinks enough fluids to stay hydrated while fighting the infection. Dehydration can make symptoms worse and slow down recovery.
Exercise & Movement
During the illness, limit active play and encourage quiet activities. Most children won't feel like running around when they're sick anyway. Gentle activities like reading books or quiet play are better choices. Once your child starts feeling better, you can slowly return to normal activities as they tolerate them. Don't rush back to physical activity or daycare right away. Let your child lead the way and rest as much as they need.
Prevention
Wash hands frequently with soap and water, especially before touching babies or young children
Keep children away from people who are sick, particularly during RSV season from fall through spring
Avoid crowded places during peak virus season when possible, especially with very young babies
Don't expose children to cigarette smoke, as this significantly increases the risk of severe bronchiolitis
Ask your healthcare professional about current RSV prevention options. Depending on age, season, and maternal vaccination history, protection may involve an RSV antibody for the baby or vaccination during pregnancy.
Clean and disinfect toys and surfaces regularly, especially during illness outbreaks
Breastfeed if possible, as breast milk provides antibodies that help protect against infections
Ask visitors to wash their hands and avoid getting too close if they have any cold symptoms. Teach older siblings to cover their coughs and sneezes with their elbows. During winter months, keep your baby away from crowded stores and public places when you can. These simple steps help protect your baby from catching bronchiolitis and other viruses.
Frequently Asked Questions
Most children feel better within 1-2 weeks. The cough may linger for several more weeks even after other symptoms improve. Very young babies may take longer to fully recover.
Children should stay home until they're fever-free for 24 hours and feeling well enough to participate in activities. This helps prevent spreading the infection to other children.
Is bronchiolitis the same as pneumonia?
No. Bronchiolitis affects the small airways, while pneumonia affects the air sacs in the lungs. However, some children with bronchiolitis may develop pneumonia as a complication, which requires different treatment approaches.
Can children get bronchiolitis more than once?
Yes. Children can get bronchiolitis or similar viral illnesses more than once, and the severity can vary.
Bronchiolitis doesn't cause asthma, but children who get severe bronchiolitis may be more likely to develop asthma later. This connection is still being studied by researchers.
Still have questions?
Consult with a healthcare professional for personalized advice.