It usually starts with a stuffy nose and a small cough. A couple of days later, your baby is coughing harder, breathing faster, and losing interest in feeds. From fall through spring, that pattern often turns out to be RSV.
Respiratory syncytial virus is so common that almost every child catches it before age 2. Most kids handle it like a cold. Young babies are the exception, and they can get very sick. Here’s how to spot RSV, care for it at home, and protect your baby before the season peaks.
What Is RSV?
RSV is a respiratory virus that spreads the same way colds do, through droplets, hands, and shared surfaces. In older kids it stays in the nose and throat. In babies and toddlers, it can travel down into the smallest airways of the lungs and cause bronchiolitis or pneumonia.
RSV is the most common reason babies under 1 are hospitalized. According to the American Academy of Pediatrics (AAP), RSV usually starts circulating in the fall, peaks in December or January, and continues into spring. An estimated 58,000 to 80,000 U.S. children under 5 are hospitalized with it each year.
Symptoms of RSV
RSV typically looks like a cold at first:
- Runny or stuffy nose and sneezing
- Cough, dry or wet
- Fever of 100.4°F or higher
- Fussiness and a hoarse cry
- Poor feeding
Symptoms are usually at their worst on days 3 to 5 and last 7 to 14 days, though a cough can linger longer. Newborns can be harder to read. The CDC notes that in very young infants, irritability, low activity, and breathing trouble may be the only signs.
Signs RSV Has Reached the Lungs
When RSV causes bronchiolitis, you may see:
- Fast breathing
- Wheezing, a whistling sound when breathing out
- Nostrils flaring or the head bobbing with each breath
- Grunting while breathing
- Belly breathing, or skin tugging in between the ribs or at the base of the neck (retractions)
Early RSV can be hard to tell apart from a cold or the flu, and in some children it also causes croup, with a barking cough. Your pediatrician can help sort out which it is.
Who Is at Higher Risk?
Any child can get very sick from RSV, but the risk is highest for babies younger than 6 months, babies born prematurely, and children with chronic lung or heart disease, weakened immune systems, or certain neuromuscular conditions. Exposure to tobacco smoke raises the risk too.
How RSV Is Diagnosed
Your pediatrician can usually diagnose RSV or bronchiolitis with a physical exam and a quick oxygen reading from a small sensor on the finger or toe. A nasal swab may be used to confirm RSV or rule out other viruses.
Caring for Your Child at Home
There’s no specific medicine for RSV, and antibiotics and steroids don’t help. Most children recover at home with good supportive care:
- Clear the nose before feeds and sleep. Babies breathe mostly through their noses, so a stuffy nose can make feeding hard. Use saline drops, then gentle suction.
- Offer smaller, more frequent feeds. Babies with RSV tire out quickly. Breastfed babies don’t need extra water. Watch for signs of dehydration.
- Run a cool-mist humidifier. Dry air makes coughs worse, and indoor air in Arvada gets very dry once the heat comes on.
- Treat fever carefully. Acetaminophen can help, and ibuprofen is an option after 6 months. If your baby is younger than 12 weeks and has a fever, call us before giving any fever medicine.
- Skip cough and cold medicines and aspirin. For children 1 year and older, a little honey can soothe a cough. Never give honey to babies under 1.
- Keep safe sleep habits. Place your baby on their back to sleep, even when they’re congested.
How to Protect Your Baby From RSV
Babies now have two strong ways to be protected, and according to the CDC, most babies need only one of them:
- RSV vaccine during pregnancy. Given at 32 through 36 weeks of pregnancy, between September and March, when the baby is due during RSV season. The AAP reports it lowers a baby’s risk of RSV hospitalization by 57% in the first 6 months.
- RSV antibody shot for the baby. A single dose of nirsevimab or clesrovimab, given at the hospital after birth or at a checkup, for babies younger than 8 months heading into their first RSV season. It works right away, lasts through a typical season, and is about 80 to 90% effective at preventing RSV hospitalization.
Some children ages 8 to 19 months with certain health conditions should also be protected in their second season. The AAP expanded that list in September 2026. Protection is still recommended after a past RSV infection, because children can catch RSV again. The shot can be given at the same visit as your baby’s routine immunizations. Ask us which option makes sense for your family.
Everyday habits still count. Wash hands often, keep your baby away from anyone with a cold, avoid crowds when you can, and don’t let anyone smoke around your child. Breast milk also passes along antibodies that help fight infection. These steps help against other common winter illnesses too.
When to Call the Doctor
Call 911 if your child:
- Is struggling for each breath or can barely cry or speak
- Has pauses in breathing or stops breathing
- Has bluish lips or face when not coughing
Go to the ER now if your child:
- Has skin pulling in between the ribs with each breath (retractions)
- Doesn’t seem alert when awake
Call our office right away if your child:
- Is younger than 6 months and getting worse in any way
- Has fast breathing, wheezing, flaring nostrils, or grunting
- Is taking less than half of their usual feeds
- Shows signs of dehydration, such as no urine in 8 hours, dark urine, a very dry mouth, or no tears
- Is younger than 12 weeks with a fever, or has a fever over 104°F at any age
- Is in a high-risk group and seems to be getting worse
Call within a day if your child:
- Has ear pain or drainage from the ear
- Has had a fever for more than 3 days
- Isn’t starting to improve after 7 days
Not sure what to do? Our online symptom checker can help, or call our office. With a baby, it’s always okay to call about breathing.
Final Thoughts
For most kids, RSV means a rough week of coughing and runny noses followed by a full recovery. For young babies, the best protection happens before they ever get sick, which is why fall is the time to talk about RSV immunization.
If you have questions about RSV symptoms or protection for your baby, call Indian Crest Pediatrics at (303) 422-7677. Our pediatricians in Arvada are happy to talk through your options at your baby’s next visit.