“They’re probably just teething” is the most common explanation for a fussy baby — and it’s right about half the time. The problem is that blaming everything on teething can cause parents to miss real illness. Here’s how to tell the difference.
Quick answer: Teething causes drooling, gum swelling, mild irritability, chewing on everything, and possibly a low-grade temperature (under 100.4°F). It does NOT cause high fever (100.4°F+), diarrhea, vomiting, rash on the body, or ear pulling. If your baby has these symptoms, look for another cause.
What Teething Actually Causes
Research studies on teething symptoms consistently find these are truly associated with tooth eruption:
Confirmed teething symptoms:
- Increased drooling — often starts weeks before the tooth appears
- Gum swelling and tenderness — you may see or feel a bump
- Chewing and biting everything — counter-pressure on gums feels good
- Mild fussiness — especially in the 1-2 days before the tooth breaks through
- Slightly elevated temperature — up to 99.5-100.3°F, but NOT a true fever
- Sleep disruption — discomfort can interrupt sleep patterns
- Decreased interest in feeding — sucking can increase gum pain
- Facial rash from drool — irritation on chin and cheeks from constant moisture
What teething does NOT cause:
Research consistently shows teething does not cause:
- True fever (100.4°F or higher) — if your baby has a real fever, something else is going on
- Diarrhea — the old “teething causes loose stools” theory is largely debunked
- Vomiting
- Body rash (not from drool)
- Severe congestion or cough
- Ear infection — despite the ear-pulling association
The Timing Trap
Teething typically occurs between 4-7 months for the first teeth and continues through age 2-3. This overlaps perfectly with:
- The end of maternal antibody protection (around 6 months)
- Starting daycare (exposure to viruses)
- Putting everything in their mouth (more germs)
So babies start getting sick more often at the same time they start teething. Correlation, not causation.
How to Tell: A Decision Framework
Probably teething if:
- Temperature is under 100.4°F
- Symptoms are mild — fussy but consolable
- Drooling increased significantly
- Baby is chewing on everything more than usual
- You can see or feel a bump on the gums
- Symptoms come and go over days to weeks
- Baby is otherwise eating, sleeping, and playing normally (with mild disruption)
Probably sick if:
- Temperature is 100.4°F or higher — this is a fever, not teething
- Vomiting or diarrhea is present
- Baby is unusually lethargic or inconsolable
- Runny nose with colored mucus (clear is okay, green/yellow suggests infection)
- Cough is present, especially if worsening
- Rash on body (not just drool rash on face)
- Loss of appetite is severe — not just decreased interest
- Symptoms are getting progressively worse over 24-48 hours
Could be both:
Sometimes babies are teething AND sick at the same time. If any “probably sick” signs are present, treat as illness even if teething is also happening.
Teething Pain Relief
For babies 3-6 months:
- Cold teething ring — chill in the refrigerator (not freezer)
- Frozen washcloth — wet, wring out, and freeze. Let baby gnaw on it
- Gentle gum massage — clean finger rubbed on the gums
- Acetaminophen for significant discomfort (check with your doctor first for babies under 6 months)
For babies 6+ months:
- All of the above, plus:
- Ibuprofen (Motrin) — the anti-inflammatory effect is particularly helpful for gum swelling
- Cold foods — chilled fruit in a mesh feeder, cold yogurt
- Use our dosage calculator for correct medication amounts
What to avoid:
- Teething gels with benzocaine — FDA warns against use in children under 2 (risk of methemoglobinemia)
- Homeopathic teething tablets — FDA has warned about inconsistent ingredient levels
- Amber teething necklaces — choking and strangulation hazard with no proven benefit
- Frozen objects that are too hard — can damage gums. Chilled is better than frozen solid
When to Call Your Pediatrician
Don’t assume it’s “just teething” and call if:
- Fever is 100.4°F or higher — especially in a baby under 3 months
- Baby is not eating at all for more than one full day
- Sleep is severely disrupted for more than 3-4 nights
- You see blood on the gums (small amounts are normal during eruption, but persistent bleeding isn’t)
- Facial swelling beyond normal drool rash
Let TriageNest sort it out. When you’re not sure if it’s teething or illness, run a symptom triage — it evaluates the full picture including age, temperature, behavior changes, and associated symptoms to determine if medical attention is needed. Get started free.
Teething is a normal developmental process that can cause mild discomfort. When in doubt about whether your baby is teething or sick, err on the side of caution and consult your pediatrician.
