Teething and baby sleep: how to tell it apart from a regression
They've been sleeping terribly for a few nights, drooling more than usual and putting everything in their mouth. Is it teething? Sometimes, yes — but teething gets blamed for a lot more bad nights than it actually causes. Here's how to recognize it, how it differs from a sleep regression or an illness, and how to support them while it lasts.
Why teething seems to get worse right at night
During the day there's plenty to distract them: play, faces, noise. At night, with everything quiet, the discomfort in the gums is easier to notice, and lying flat can increase the feeling of pressure. That's why the discomfort often seems to concentrate right at bedtime, even when they look calmer during the day.
Another reason it's hard to pinpoint: it overlaps with other things. First teeth and molars come through at the same ages when sleep regressions tend to show up, and it's very easy to blame the tooth for what's really a developmental leap.
When teeth usually come in
| Approximate age | What usually comes through |
|---|---|
| 6 – 10 months | First teeth (incisors) |
| 12 – 16 months | First molars |
| 16 – 22 months | Canines |
| 20 – 33 months | Second molars |
These ages are approximate, and some babies get their first tooth much earlier or later without it meaning anything unusual. Molars tend to be the ones that bother them most, since they're broader than incisors.
Three possible explanations for a rough patch
The discomfort tends to concentrate around when each tooth comes through, not last for weeks on end.
- Drools more than usual and puts everything in their mouth
- Bites or rubs their gums, which may look red or a bit swollen
- More irritable, but between rough moments they seem fairly normal
Here it isn't about a tooth, but about a developmental leap: something new that keeps their brain active right when it should be winding down.
- The bad nights stretch on for several weeks in a row
- It coincides with something new: crawling, walking, talking, more separation anxiety
- There are no clear signs of discomfort in the mouth
Some symptoms shouldn't simply be put down to teeth:
- Fever (teething doesn't usually cause a high fever)
- Severe diarrhea, vomiting, or a rash
- Tugging at an ear, seeming very unwell, or clearly refusing to eat
If you notice any of these, check with your pediatrician instead of waiting for the tooth to come through.
How to support them without losing what you've already built
While the discomfort lasts, what helps most is staying with them, not letting them cry: if they're genuinely uncomfortable, they need you close. That doesn't mean starting over or changing the routine — on the contrary, repeating the same sequence every night is what gives them security when something is bothering them.
A chilled teether (never frozen solid) or a clean, cool cloth can help soothe them. Avoid teething necklaces, because of the risk of choking or strangulation, and check with your pediatrician before using gels or pain relievers.
This is the what and the when — not how to hold your routine
Knowing how to tell teething from a regression already saves you a lot of doubt at 3 a.m. But to hold your routine and your progress through a patch like this — without letting them cry and without going back to square one — the exact steps are in the full guide, tailored to their age and pace.
See my personalized guideFrequently asked questions
Can I keep the sleep routine going while they're teething?
Yes, and it usually helps. Keeping the same routine every night gives them security when they're most uncomfortable. What changes is that they may need more support for a few days, without that meaning you're starting over.
Does teething cause a fever?
Teething doesn't usually cause a high fever. If your baby has a fever, severe diarrhea, or seems very unwell, don't just put it down to teething: check with your pediatrician.
How long does the discomfort from a new tooth last?
Usually the discomfort is concentrated in a few days around when each tooth comes through, not spread over weeks. If the bad nights drag on for weeks, there's probably another cause, such as a sleep regression.