Teething gets blamed for an enormous amount of crying between 6 and 12 months. Sometimes it's the right answer. Often it isn't — and the reason that matters is that the teething window is also the window in which babies first encounter most of the common childhood infections. Telling the difference reliably comes down to a handful of features, and a useful checklist for the moments you're unsure. For the wider picture see our complete guide to child health.
What Teething Crying Actually Looks Like
When a tooth is coming through, you usually see this pattern — and only this pattern:
- Mildly grumpier than usual, with a soft edge of irritability rather than full distress.
- Chewing on fingers, the corner of muslins, the side of the cot, the strap of the high chair. Counter-pressure on the gum genuinely takes the edge off.
- Heavy drooling — chin and bib constantly wet, sometimes a low-grade contact rash on the chin.
- Slightly more night waking for a night or two around eruption — not a fortnight of disrupted sleep.
- Possibly a bit of cheek-rubbing or ear-tugging on the affected side (the gum nerves refer up the jaw line).
The defining features are mild, local, brief. The fussiness peaks the day or two before the tooth breaks through, then lifts once it does. If you can run a finger along the gum and feel the hard edge of a new tooth, the case is closed.
If what you're seeing is louder, longer, or more systemic than that picture, the answer is not teething.
Symptoms That Are Not Teething
The evidence on this is now well-established. Prospective studies that have actually filmed gums and tracked daily symptoms in real time find no causal link between tooth eruption and any of the following:
A temperature above 38°C. Some babies have a few-tenths-of-a-degree blip around eruption. A real fever is not from the teeth — it's a viral illness, an ear infection, or occasionally something more serious. Take the temperature; don't shrug it off as the molars.
Diarrhoea. Almost universally believed; not borne out by the data. Loose stools at 6–12 months are usually viral gastroenteritis (also extremely common at this age — the overlap is a coincidence, not a cause).
Persistent vomiting. Not a feature of teething. Worth assessment in its own right.
A body rash. Drool rash on the chin and cheeks is real, but it's contact irritation from saliva, not a systemic rash. Anything more widespread — particularly with fever — is not teething. A non-blanching rash (one that doesn't fade under pressure on a glass) is a paediatric emergency at any age.
Runny nose, persistent cough, wheeze, or noisy breathing. Coincidence with teething, not caused by it.
Inconsolable crying for hours, or a baby who looks unwell. A teething baby is grumpier than usual but is recognisable as themselves and is settled by ordinary comfort measures. A baby crying for hours who can't be soothed warrants a same-day GP or A&E review — possibilities include otitis media, intussusception (older infants — bouts of crying with pallor and drawing knees up), urinary infection, or the early phase of an unwell illness that hasn't yet declared itself.
The Run-Through When You're Not Sure
If your baby is grumpier than usual and teeth are clearly on the way, teething is plausible — but don't stop there. Run through the following before you decide:
- Temperature. Take it. Above 38°C means look elsewhere.
- Ears. Are they tugging persistently? Crying when laid flat (classic for ear infection — pressure builds up when horizontal)? Discharge from the ear?
- Wet nappies. Six or more in 24 hours is reassuring. A noticeable drop suggests dehydration or unwellness.
- The cry itself. Is it the usual pitch, or is it higher and more urgent? Parents are usually right that "this isn't her normal cry" — trust that instinct.
- Response to comfort. Does feeding, holding, or distraction settle them? A baby who stays inconsolable through everything you'd normally try is signalling something more.
- General appearance. Eye contact, recognisable smiles, normal interest in surroundings between the crying — reassuring. Floppy, withdrawn, blank-faced — not reassuring.
If you answer "yes" to any of the concerning options, treat it as a separate problem and seek advice. A teething baby with a fever has a fever; the teeth are incidental.
Why the Timing Trap Matters So Much
The second half of the first year is simultaneously the peak period for tooth eruption and the peak period for first encounters with common infections. Babies who have been cocooned by maternal antibodies and home life start meeting other children, the wider environment, and a steady stream of viruses. Gastroenteritis, otitis media, respiratory viruses, roseola, hand-foot-and-mouth, and first urinary tract infections all cluster in this window.
Teething overlaps with all of them constantly. Which means teething is always a plausible explanation for fussiness — and that's exactly why it gets used as the default, and why the real cause sometimes goes missed for a few extra days. The cost of getting it wrong in the careful direction (assessing a baby who turns out just to have been teething) is small. The cost of getting it wrong in the other direction (sending home an unwell baby with "must be the teeth") can be large.
When to Get Them Seen
Same-day GP review for any of:
- Temperature ≥38°C in a baby under 3 months, or ≥39°C in a 3–6 month old, or any fever lasting more than 5 days
- A baby who looks unwell, floppy, drowsy, or "not themselves"
- Persistent inconsolable crying that comfort measures don't touch
- Vomiting that won't settle, green/yellow vomit, or fewer wet nappies
- A non-blanching rash (do the glass test)
- Difficulty breathing, fast breathing, sucking-in around the ribs
- Persistent ear pulling with fever or worsening when laid flat
- Bouts of crying with pallor and knee-drawing in a 3–9 month old (consider intussusception — A&E)
The Practical Bottom Line
Teething is a diagnosis of mild, local, brief gum discomfort. It is not a catch-all for anything difficult that happens in the second half of the first year. When the picture fits — drooling, chewing, a few days of grumpiness, a tooth visibly through the gum — treat it gently and move on. When the picture doesn't fit, trust your instincts and get the baby seen. Both responses are useful; conflating them is what gets people into trouble.
Key Takeaways
Teething produces a particular kind of crying — low-grade fussiness for a day or two with heavy drooling and chewing, peaking just before the tooth pops through, lifting once it does. It does not produce inconsolable hours-long crying, fever above 38°C, persistent vomiting, diarrhoea, body rashes, or a baby who looks ill. The diagnostic trap is that the teething window (6–12 months) is exactly the same window in which babies catch their first viruses, get their first ear infections, and meet gastroenteritis — so 'it's just teething' is the single most common reason a real illness gets seen too late. The rule of thumb: if a teething baby seems unwell beyond the gum, run through the checklist (temperature, ear pulling, wet nappies, cry quality, response to comfort) and treat anything outside the local-and-mild picture as something else. When in doubt, get them seen — teething is a diagnosis of mild localised gum discomfort, not a catch-all.
