How to Treat a Baby's Runny Nose

It is never fun dealing with a baby's runny nose. Seeing your little one struggle with endless snot can be tough, but nonetheless, it is a common (and usually normal) part of being a tiny human. 

That said, it can be confusing to determine whether your baby’s runny nose is the result of a cold or allergies, or something a bit more troubling, such as RSV. Let’s take a look at the main causes of a runny nose in babies, how to tell the difference between common illnesses, their treatment options, and when to contact a health care provider. 

Causes of a Runny Nose in Babies

There are several reasons why a baby might come down with a runny nose, ranging from illnesses to allergies and more. “The main causes of runny nose in children are viral infections, bacterial infections, and environmental allergies,” says Nicole Wawrin, MD, a pediatrician at Weill Cornell Medicine. “Overwhelmingly, viral infections are the biggest culprits of a runny nose in children.”

Some of the most common viral infections in children include: 

• Cold and flu
• Sinus infections
• RSV (or respiratory syncytial virus)
• COVID-19

“To the frustration of many parents, young children may have a runny nose for months on end simply due to sequential viral infections,” adds Dr. Wawrin.

Allergies can also be the culprit behind your child’s runny nose. Florencia Segura, MD, FAAP, a board-certified pediatrician at Einstein Pediatrics, explains that seasonal allergies are more common in toddlers, and older children, rather than in babies. 

Is My Baby's Runny Nose a Cold, Flu, or Something Else?

If your little one’s nose is running, it can be hard to distinguish whether you’re dealing with the common cold, influenza (the flu), or another infection, such as COVID-19 or RSV.

“It can be very hard to distinguish which specific infection is the cause of a child's respiratory symptoms,” says Dr. Wawrin. “For example, children with COVID and flu can present very similarly with fever, cough and congestion, and fatigue. Generally, if a child is breathing comfortably and without prolonged fever or symptoms, we don't even need to know the specific ‘germ’ because it typically does little to change treatment,” she says. 

Cold, Flu, and COVID-19 Symptoms in Babies and Children

While these illnesses can present similarly, there are some key differences between the common cold and the flu:

• Cold symptoms tend to come on gradually, while flu symptoms appear more abruptly 
• A fever is usually a sign of the flu and is less common in colds
• Chills, cough, chest discomfort, headache, and weakness are more common with the flu
• Runny or stuffy nose, sore throat, and sneezing are more common with a cold 

Ultimately, cold symptoms are typically much milder than those of the flu. Similarly, COVID-19 often starts out very similar to a cold, although it can also cause a fever, says Dr. Segura. The CDC states that fever and cough are the most common symptoms of COVID-19 in children, but they may also experience sore throat, runny nose, headache, fatigue, shortness of breath, or gastrointestinal symptoms such as nausea, vomiting, or diarrhea.

Dr. Segura adds that if you have cold symptoms and have been around someone with COVID-19, you should get tested to find out if you have it, too. Additionally, if you are concerned about any of your baby's symptoms, you should get in touch with a health care provider.

RSV and Croup Symptoms in Babies and Children

If your child has been infected with something more serious, such as RSV, there are other symptoms to look out for. 

“We can typically tell if a child has a more serious infection if they are breathing abnormally or have prolonged copious congestion, cough, or fever,” says Dr. Wawrin. “RSV tends to be one of the most feared infections by parents and pediatricians because it can cause sudden respiratory deterioration in some young children, requiring ER visits or hospitalizations.”

If your child has RSV, they are also likely to exhibit symptoms such as: 

• Fast breathing
• Flaring of the nostrils
• Grunting during breathing
• Belly breathing
• Wheezing

That said, Dr. Wawrin explains that many children who test positive for RSV may only have mild cold symptoms and may not appear very sick at all. If you are unsure, a trip to a health care provider's office is the best way to determine whether RSV is the cause of your child’s illness. 

Along these lines, croup is another potential illness that can cause concern. It is also known as a “barking” cough because of its raspy sound, similar to a seal’s bark. Your child may also make a high-pitched, squeaky noise when they breathe.

Croup may begin with similar symptoms to a cold or flu, such as a stuffy nose, runny nose, or fever, but the barking cough appears as the voice box and windpipe become irritated or swollen. If you suspect that your child has croup, it’s important to visit a pediatrician or health care provider, where they may suggest a chest X-ray depending on its severity and response to treatment.

What Do Different Snot Colors Mean in a Baby's Runny Nose?

It can be alarming to see thick yellow or green snot hanging from your baby's nose. What does it mean, exactly?

“Mucus can be clear, yellow, or green,” says Dr. Segura. “The presence of immune cells that fight infections typically alters the mucus color.” She explains that the initial appearance of mucus is part of your child’s inflammatory response from the body to help clear a virus from the nose and sinuses. “After two to three days, the body's immune cells fight back, changing the mucus to white, yellow, or green,” she adds. 

Although alarming, Dr. Wawrin explains that contrary to popular belief, green mucus does not always indicate a bacterial infection. “Pediatricians look more at a child's overarching set of symptoms and physical exam when deciding whether a child is sick with a virus or bacteria,” she says. “If your child has a lot of green mucus, it is still a good idea for him to get a check-up, but it doesn't necessarily mean that he will be prescribed a course of antibiotics during the visit.”

The most common snot colors and their meanings include: 

• Clear: Normal, but could be a sign of a cold or allergies (especially if it’s stringy)
• White: Your child is likely coming down with a cold or upper respiratory infection
• Yellow and green: The body is trying to fight off infections and may show up after a few days of being sick

Is My Baby's Runny Nose a Sinus Infection?

If you suspect your baby has a sinus infection, here are the main symptoms to look out for: 

• Cold symptoms such as runny/stuffy nose and/or cough lasting more than 10 days without improvement
• Thick, yellow nasal mucus accompanied by a fever that lasts three or four days in a row
• A bad headache, typically around the eyes, that can get worse upon bending over
• Swelling and dark circles around the eyes, which may be more prominent in the morning

If you suspect a sinus infection, it’s important to contact a health care provider. If it is found to be bacterial sinusitis, your child will likely be given an antibiotic treatment.

Treatment for a Runny Nose

Luckily, there are various forms of treatment for a runny nose, depending on your child’s age and accompanying symptoms. As always, be sure to discuss any treatments or remedies with a health care provider.

At-Home Treatment 

“Home remedies can be just as helpful with cold symptoms as OTC medications,” says Dr. Wawrin. She suggests the following: 

• Honey as a cough suppressant for children over 1 year of age (either taken by a spoon or mixed in warm fluid)
• A cool-mist humidifier for congestion
• Children’s vapor rub to soothe and open nasal passages (especially for sleep). But do not put it directly in the nose as it can block their airway.
• A child-friendly product to help remove mucus, such as a suction bulb or NoseFrida

Saline nose drops or spray can also help relieve the stuffiness, says Dr. Segura. She also stresses the importance of keeping your little one hydrated! “The most important thing to do is to ensure they are hydrating with water, breastmilk, formula, milk, juice, or broth. This will help replace any fluids lost caused by a runny nose or sweating from a fever,” she explains.

Over-the-Counter Treatment

For OTC treatment such as cold and flu medications, Dr. Segura provides this handy guide: 

• Under age 4: Do not give them any cold medications, as they are not safe for young children
• Ages 4 to 6 years: Cough medicine should be used only if recommended by a health care provider
• After age 6: Cough medicines can be used, but always ensure you follow the medication’s instructions

However, it is always best to check with a health care provider before giving OTC medications to children of any age. Dr. Segura points out that aspirin should never be given to any child under the age of 18, as it can cause a life-threatening condition called Reye syndrome.

“When giving your child acetaminophen (like Tylenol) or other non-prescription medicines, never give more than the recommended dose,” she notes, adding, “Your doctor will prescribe antibiotics if they are concerned about a bacterial infection such as sinusitis, ear infection, or pneumonia.” 

When to Call a Healthcare Provider About Your Baby's Runny Nose

Dr. Wawrin states that you should always contact a pediatrician or health care provider if your child's breathing is consistently faster than usual or if they exhibit signs of respiratory distress. “For example, your child's nostrils are flaring or muscles in the chest/neck are moving more prominently while they are breathing,” she says. “Any abnormal noises that your child is making from her throat or chest while breathing also need to be passed by the pediatrician.”

Other warning signs that warrant a call to a health care professional include: 

• Any child under 3 months old that shows signs of an illness (call as soon as they appear)
• A temperature of 100.4°F or higher in children 3 months old or younger
• A temperature over 102°F in a child of any age
• They are excessively tired or irritable
• They are having trouble breathing (flared nostrils, fast breathing)
• Their lips or nails turn blue

Dr. Segura adds that children with a cold and nasal congestion may also develop a bacterial ear infection. “Suppose a child develops a fever (temperature higher than 100.4°F or 38°C) after the first three days of cold symptoms along with fussiness, ear pulling, irritability, and crying while lying down. In that case, an ear infection may be to blame,” she says. 

In terms of a fever, you should also give a health care provider a call if your little one is still acting fairly sick even after a fever is brought down, the fever lasts longer than 24 hours in children younger than 2 years old, or if it lasts more than three days (72 hours) in children 2 years of age or older. 

The Bottom Line 

Remember, a long-lasting runny nose in children can be common! 

“Sometimes, kids seem like they have a runny nose all winter long,” says Dr. Segura. “The reason is that the symptoms of a cold are usually worst during the first 10 to 14 days. It is also not unusual for a child to develop a second cold as the symptoms of the first cold are resolving; this can make it seem as if the child has a single cold that lasts for weeks or even months, especially during the fall and winter.”

Even more commonly, says Dr. Wawrin, children aren't great at blowing their noses and a lot of the mucus is swallowed, which can be irritating to the stomach. Always contact a health care provider if you are unsure whether your child’s runny nose is something more serious such as RSV, especially if you have a newborn or infant. 

Lastly, be sure to stock up on tissues during the winter months—you can never have too many! Runny noses may be a sticky, uncomfortable part of being a kid, but most of the time, they resolve on their own.