GUIDE
The evidence-supported signs are gum swelling, drooling, and the urge to chew. That is largely it.
Teething gets blamed for everything from fever to rashes to bad days. The research tells a much simpler story. Here are the symptoms that are actually linked to teething — and the ones that mean something else is going on.
If you search for "teething symptoms" online, you will find lists that include everything from fever to diarrhea to rashes to congestion to ear pulling to mood changes. The problem is that most of these symptoms have little to no support in the medical literature as actual teething symptoms.
This matters more than you might think. When parents (and even some well-meaning providers) attribute every symptom to teething, real illnesses sometimes get missed. A baby with a 102°F fever does not have "bad teething" — they have an infection that may need treatment. A baby with persistent diarrhea does not have "teething diarrhea" — they may have a stomach bug that requires monitoring for dehydration.
The landmark studies on this topic — Macknin et al. (2000), Wake et al. (2000), and the comprehensive systematic review by Massignan et al. (2016) — paint a much simpler picture of what teething actually causes. The evidence-supported symptoms are gum-related (swelling, tenderness, the urge to bite), drool-related (increased saliva, drool rash), and behavioral (mild irritability). That is largely it.
This does not mean your baby's discomfort is not real. Teething pain is genuine, and some babies clearly have a harder time than others. But understanding which symptoms are actually teething and which ones point to something else is one of the most important distinctions you can make as a parent.
| Symptom | Evidence Level | Details |
|---|---|---|
| Gum swelling, redness, or tenderness | Strongly supported — consistently found across multiple studies | The gum directly over the erupting tooth may appear swollen, red, or have a bluish-white bump. This is the most reliable physical sign. |
| Increased drooling | Strongly supported | Drooling often increases significantly during active teething. It can begin weeks before a tooth appears and may cause drool rash around the mouth. |
| Desire to bite or chew on objects | Strongly supported | Counter-pressure on the gums provides relief. Babies instinctively seek firm objects to chew during teething. |
| Irritability or fussiness | Moderately supported | Mild, intermittent irritability — not all-day inconsolable crying. The fussiness typically peaks around eruption and resolves quickly. |
| Gum rubbing | Moderately supported | Babies may rub or press on their gums with their fingers or fists. |
| Mild sleep disruption | Weakly to moderately supported | Some studies show a slight increase in night waking around tooth eruption, but the effect is modest and short-lived. |
| Slight temperature elevation (below 100.4°F / 38°C) | Weakly supported | Some studies show a very slight temperature increase, but this does NOT reach the level of true fever. Any temperature at or above 100.4°F is NOT teething. |
This section may surprise you, because some of these symptoms have been attributed to teething for generations. But the evidence is clear: teething does not cause fever, diarrhea, vomiting, body rashes, cough, or congestion.
Fever: Studies by Wake et al. (2000) and Macknin et al. (2000) both found that teething may cause a very slight temperature elevation — up to about 100°F (37.8°C) — but does NOT cause true fever (defined as 100.4°F / 38°C or higher). The systematic review by Massignan et al. (2016) confirmed this finding. A baby with a genuine fever has an infection of some kind, even if a tooth happens to be coming through at the same time.
Diarrhea: No controlled study has established a causal link between teething and diarrhea. The timing coincidence — teething peaks during the same months that babies are putting everything in their mouths and encountering more pathogens — explains why parents see the association. But the diarrhea is caused by what the baby picked up from chewing on that grocery cart handle, not by the tooth itself.
Rash (beyond drool rash): Drool rash — redness and irritation around the mouth, chin, and neck from constant moisture — is genuinely teething-related. But a rash on the trunk, limbs, or other areas of the body is not caused by teething and suggests a viral exanthem, allergic reaction, or other condition.
Congestion and runny nose: Teething does not cause nasal symptoms. The reason babies seem to get colds while teething is that the teething age coincides with the age when maternal antibodies decline and babies encounter more viruses, especially if they are in group childcare.
| Symptom | Is It Teething? | What It Might Actually Be |
|---|---|---|
| Fever (100.4°F / 38°C or higher) | Not supported — multiple controlled studies show teething does not cause true fever | Viral or bacterial infection. Evaluate based on age, fever height, and associated symptoms. |
| Diarrhea | Not supported — no causal link established in controlled research | Viral gastroenteritis, food sensitivity, or other GI issue. The timing overlap with teething is coincidental. |
| Vomiting | Not supported | Stomach virus, food intolerance, or other illness. Vomiting is never 'just teething.' |
| Congestion or runny nose | Not supported | Upper respiratory infection (common cold). Teething age coincides with the age of frequent viral infections. |
| Body rash (not localized to mouth area) | Not supported | Viral exanthem, allergic reaction, eczema flare, or other dermatological cause. |
| Cough | Not supported | Upper respiratory infection, post-nasal drip, or other respiratory cause. |
| Ear pulling with fever or irritability | Not supported as a teething sign when accompanied by fever | Ear infection (otitis media). Ear pulling alone may be teething-related, but with fever it needs evaluation. |
| Refusal to eat for more than 1-2 days | Prolonged feeding refusal is not typical of teething | Illness, oral thrush, or other condition. Brief appetite reduction around eruption is normal, but prolonged refusal is not. |
If you are trying to figure out whether your baby's fussiness is teething or something else, a few days of tracked data — sleep, feeds, diapers, and symptoms — gives you a much clearer picture than trying to piece it together from memory. tinylog tracks everything in one place, so you can see what changed and when.
There is a very good reason why teething has been blamed for fever, diarrhea, and colds for centuries: the timing lines up perfectly. Babies start teething between 4 and 12 months. This is also the exact window when:
So a baby who is cutting teeth, catching their third cold of the month, and having loose stools from a stomach bug looks like a baby with "teething fever and teething diarrhea." But correlation is not causation. The fever is from the virus. The diarrhea is from the gastroenteritis. The tooth is just along for the ride.
This is not just an academic distinction. When parents attribute genuine illness symptoms to teething, they may delay seeking care that could prevent complications. A fever over 100.4°F in a young infant always deserves evaluation, regardless of whether a tooth is visible in the gum.
Pediatricians have a complicated relationship with teething. They know it causes real discomfort. They also see, on a daily basis, the consequences of over-attribution — sick babies whose symptoms were dismissed as "just teething."
Teething makes babies uncomfortable, not seriously ill. A teething baby may be fussy and drooly, but they should not be lethargic, inconsolable, or visibly unwell. A baby who seems truly sick — even if they are teething — needs evaluation.
If symptoms last more than a few days, it is probably not teething. Teething symptoms for any individual tooth peak around the day of eruption and typically resolve within a day or two. Symptoms that persist for a week or more have a different cause.
You can always call. No pediatrician has ever been annoyed by a parent who called because they were not sure if symptoms were teething or illness. The call is the right move. The worst that happens is reassurance. The best that happens is catching something that needed treatment.
Trust your instincts. If something feels off — if your baby seems sicker than "teething fussy" — trust that feeling. Parents who know their babies well are often right when they sense something is wrong, even if they cannot articulate exactly what.
Everything else — drooling, fussiness, sleep changes — can be caused by multiple things. But if you look at your baby's gum and see swelling, redness, or a visible bump where a tooth should be, you can be reasonably confident that teething is happening. Feel along the gum with a clean finger — you may be able to feel a hard ridge or sharp point just beneath the surface.
If your baby has been 'teething' for three weeks with no tooth in sight, the symptoms you are seeing may not be teething at all. Research shows that teething symptoms are most concentrated in the days immediately before and on the day of eruption. Prolonged or worsening symptoms warrant a second look at what is actually going on.
Not every baby announces their teeth with a week of misery. Some parents discover a new tooth only when they hear it clink against a spoon or feel it during a gum check. If your baby is cutting teeth without apparent discomfort, count yourself lucky — and know that it is perfectly normal.
The most dangerous thing about teething myths is not the myths themselves — it is that they cause parents to dismiss real illness. A 102°F fever is not teething. Persistent diarrhea is not teething. A baby who is unusually lethargic or unwell is not 'just teething.' When symptoms go beyond the mild and the expected, call your pediatrician.
This guide is for informational purposes only and is not a substitute for professional medical advice. If your baby has a fever of 100.4°F (38°C) or higher, is refusing to eat, or seems unusually unwell, contact your pediatrician — these symptoms are not typical of teething alone.
