Teething or a cold? How to tell why your baby has a fever

When your baby drools nonstop and gnaws on everything, you might think, "Ah, teething is starting." But when they feel warm and get fussy, you start to wonder, "Could this be a cold?" The window from about 6 months to a year, when teething begins, is also when the immunity passed on from mom fades and minor illnesses pick up — so the two can easily look alike.

The first thing to keep in mind is how high the fever is. Teething can bring on drooling, swollen gums, biting on things, fussiness, and a slightly warm, low-grade temperature — but it is generally not thought to cause a true fever above 38℃ (100.4℉). On the other hand, when a runny nose and cough come with a fever of 38℃ or higher, it is more likely a sign of an infection like a cold. So before brushing it off with "the fever must be from teething," look at how high the fever is and whether other symptoms are present too.

There's also a safety line worth remembering. If a baby under 3 months has a fever, they should be seen right away, before you try to figure out the cause. Even after that, if a fever of 38℃ or higher comes with listlessness or poor feeding, it's best to check with your pediatrician. We'll walk through how to tell teething apart below.

Teething vs. a cold: how do the symptoms differ?

The key that separates the two is where the symptoms show up. Teething tends to cluster around the mouth — drool, gums, and the area around the lips — while an infection like a cold tends to spread through the whole body, with a runny nose, cough, fever, and digestive symptoms. Seeing where the symptoms gather makes it much easier to get a sense of the direction.

Area	Often seen with teething	Often seen with a cold / infection
Drool	Noticeably more; chin and chest often wet	May or may not increase
Gums / mouth	Gums swell and itch, so baby bites on things	Little change
Fever	Slightly warm, low-grade, usually under 38℃	Can rise to 38℃ or higher
Nose / cough	Usually none	Runny nose, congestion, cough, sneezing common
Digestive	Usually none	Vomiting or diarrhea may come along
Overall	Fussy but manages to play and feed	Listless, may feed less than usual
Other	Tugging at the ear/cheek on one side, rash around the mouth, restless sleep	Sore throat, eye discharge, warmth — spreading over the body

As the table shows, teething brings mostly local signs around the mouth, while infection spreads widely to the nose, throat, belly, and whole body. That said, because the teething window overlaps with the minor-illness window, the two can arrive at the same time. So rather than deciding "drool and fussiness must mean teething," always check whether a fever and other whole-body symptoms are present too.

Whether the fever tops 38℃ is the biggest fork in the road

Of all the signs, the one that most sharply divides the direction is how high the fever is. Teething can raise the temperature only to a slightly warm, low-grade level, and a fever above 38℃ is hard to explain by teething alone — this is a point commonly made across pediatric sources, including the American Academy of Pediatrics. In fact, a meta-analysis of more than 3,500 children (Pediatrics, 2016) found that teething may raise body temperature very slightly but does not lead to a fever of 38℃ or higher, and that the most common signs are gum irritation, irritability, and drooling. A high fever means you should be looking for another cause along with the teeth.

Temperature is usually read like this (based on an underarm reading): 37.3℃ and up is low-grade, 38℃ and up is a fever that warrants a check, and 39℃ and up is a high fever. Normal ranges differ a little by where you measure (underarm, ear, forehead), and you'll find the by-site thresholds and how to measure accurately in fever thresholds by measurement site →. A baby may run slightly warmer than usual with teething. But if the thermometer reads 38℃ or higher, it's better not to write it off as teething. Watching and waiting with "it's probably the teeth" can mean missing the early stage of an infection, which can leave your baby feeling worse.

When you're unsure, it helps to take your baby's temperature a few times over the day and jot down the trend. A low-grade temperature from teething usually doesn't swing much within a day, whereas a fever from an infection often tops 38℃ or rises and falls. Having the numbers written down also makes it easier to describe your baby's condition at the visit.

Let's clear up one misconception here. Saying "it's fine to have a fever because it's teething" is not a safe rule of thumb. Precisely because teething itself doesn't produce a high fever, a high fever is closer to a sign that you should look for another reason. We cover this in more detail in common myths about teething →.

There are signs teething wouldn't cause

The symptoms below aren't well explained by teething alone. If you see them, don't chalk them up to teething — consider that it could be an infection or another cause, and take a closer look. If several overlap or your baby seems especially unwell, check with your pediatrician.

1. A fever above 38℃, or one that won't come down

As noted, a fever of 38℃ or higher is hard to attribute to teething alone. If a fever lasts more than a day, or keeps rising and falling, it's worth checking for a separate cause.

2. Diarrhea or repeated vomiting

Slightly looser stools from swallowing a lot of drool are different from true diarrhea. If watery stools are frequent or your baby keeps vomiting, think about a digestive infection rather than teething. It deserves extra care because it can lead to dehydration.

3. Listlessness, or not playing and feeding as usual

A teething baby is usually fussy but still plays and feeds. On the other hand, if your baby is noticeably droopy, less responsive, and can't feed or sleep well, that's hard to see as teething alone.

4. A heavy runny nose or cough, or a rash over the body

A marked runny nose, congestion, or cough, or a rash spreading over the whole body, points more toward infection. The range is different from the small rash around the mouth that teething can bring.

When should you see a pediatrician?

The most confusing part is "can I watch at home, or do I need to go in?" It's hard to draw a hard line, but using your baby's age, the height of the fever, and their overall condition as a guide helps. If you see the signs below, seeing a doctor first — rather than debating whether it's teething — is the safer path.

• If a baby under 3 months has a fever, see a doctor right away, whatever the cause. At this age, fever itself is treated as urgent.
• Even after 3 months, if a fever of 38℃ or higher comes with listlessness, poor feeding, or being clearly different from usual, check with your pediatrician.
• When a fever lasts 3 or more days, or comes down and rises again repeatedly.
• Repeated vomiting or diarrhea, noticeably less urine, or a dry mouth — when dehydration is suspected.
• When your baby seems especially unwell — hard breathing, convulsions, or barely responding when woken.

How you tell fevers apart and respond also connects to seasonal infections. For distinguishing a summer cold from symptoms that look like a chill from too much air conditioning, see air-conditioning chill or summer cold? telling your baby's symptoms apart →. For how to care for a rising fever at home step by step, see what to do at home when a fever comes on →. In any case, rather than using fever reducers or home remedies on your own, when a fever is high or your baby seems unwell it's best to decide on a plan together with your pediatrician.

Frequently asked questions

Is a slight fever during teething okay to leave alone?
If it's a slightly warm, low-grade temperature and your baby is playing and feeding as usual, you can dress them lightly and keep an eye on things. But if the thermometer reads above 38℃ or there are signs of listlessness, it's safer not to write it off as teething and to check instead. Babies vary, so when it's unclear, we suggest asking your pediatrician.

Can teething and a cold come at the same time?
Yes — because the timing overlaps, they can arrive together. So it's better not to rule out an infection just because there are drool and gum symptoms. If a fever and whole-body symptoms are present too, consider that the two may have overlapped and take a closer look.

Can drool make stools looser?
Swallowing a lot of drool is sometimes said to make stools softer than usual. But if watery stools are frequent or the number rises sharply, it may be a digestive issue rather than teething — watch alongside signs of dehydration, and see a doctor if it's severe.

Can I give a fever reducer?
Whether to use medicine when there's a fever, and which one and how much, depends on your baby's age and condition, so it's hard to decide on your own. Especially with younger babies, it's safest to decide together with your pediatrician or pharmacist.

How many days does teething usually last?
It varies, but the discomfort as a single tooth comes through is usually a few days. Gum irritation, fussiness, and drooling are the most common, and the area around the mouth often stays wet as drool increases. If the discomfort drags on, or a fever of 38℃ or higher and whole-body symptoms join in, it's hard to call it teething alone — so look at those together.

My baby seems fussier at night in particular.
Teething discomfort can look more noticeable at night than during the day. For how to soothe safely overnight and what to avoid (benzocaine gels, amber necklaces, and the like), see soothing teething at night and what to avoid →.

To sum up

Teething can bring drooling, swollen gums, biting on things, fussiness, and a slightly warm low-grade temperature — but a true fever above 38℃, or a runny nose, cough, vomiting, diarrhea, or listlessness, is hard to explain by teething alone. That's why looking at both how high the fever is and whether other whole-body symptoms are present is the key to telling them apart.

Above all, a fever in a baby under 3 months should be seen right away, before figuring out the cause. Even after that, if a fever of 38℃ or higher comes with listlessness or suspected dehydration, check with your pediatrician. The point is not to miss an infection by self-diagnosing "it's probably the teeth." Babies vary, so when it's unclear, seeing a doctor rather than deciding on your own is the most reassuring path.

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Sources
American Academy of Pediatrics (HealthyChildren.org) — teething symptoms and fever
Massignan C et al., Signs and Symptoms of Primary Tooth Eruption: A Meta-analysis, Pediatrics (2016)
American Academy of Pediatrics — fever in infants and when to call the doctor