- What is teething and when does it happen?
- Baby teething timeline — when do teeth come in?
- True teething symptoms — what is actually caused by teething
- Illness symptoms — what teething does NOT cause
- Teething vs illness — side-by-side comparison guide
- Specific scenarios parents confuse most often
- Why teething and illness happen at the same time
- Safe teething relief — what actually works
- Products and remedies to NEVER use for teething
- Frequently asked questions
- When to call the doctor
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Your baby is drooling rivers, gnawing on everything in sight, and waking up crying through the night. You assume it must be teething — until the runny nose appears, or the fever climbs, or the loose stools start. Suddenly you are not so sure. Is this all just teething? Or is something else going on?
The teething vs illness question is one of the most common dilemmas faced by new parents worldwide. And it matters enormously — because misidentifying a real illness as “just teething” can lead to delayed treatment, while every sniffle and loose stool wrongly attributed to teething can create unnecessary anxiety and missed diagnoses.
This complete guide gives you a clear, evidence-based breakdown of what teething actually causes, what it does not cause, how to tell the difference from illness, and what to do in the scenarios parents find most confusing — including fever, ear infections, diarrhoea, runny nose, and rashes.
What is teething and when does it happen?
Teething is the completely normal process of a baby’s primary teeth — also called milk teeth or baby teeth — pushing through the gum tissue and emerging into the mouth. A full set of 20 primary teeth is expected to be present by around 30 months (2.5 years) of age.
Teething typically begins between 4 and 7 months of age, though some babies start as early as 3 months and others may not show their first tooth until 12 months or later. Both early and late teething within this range are entirely normal. Delayed teething — defined as no tooth by 12–18 months — is worth mentioning to your paediatrician, but even this is often simply normal variation.
Teething discomfort typically begins a few days BEFORE a tooth emerges and resolves within a few days AFTER the tooth has broken through the gum. A research study tracking 475 tooth eruptions found that symptoms were only significantly elevated in an 8-day window — 4 days before and 3 days after the tooth appeared. If your baby has been “teething” for weeks without a tooth appearing, something else is likely going on.
Baby teething timeline — when do teeth come in?
Knowing which teeth typically emerge when helps you understand whether your baby’s current discomfort is plausibly timed with teething:
True teething symptoms — what is actually caused by teething
This is where many parents are surprised. The list of symptoms that medical research has confirmed are genuinely caused by teething is actually quite short. A major study tracking 125 babies over 8 months identified the following as statistically associated with tooth eruption:
- Increased drooling — teething stimulates extra saliva production, which causes the classic rivers of drool. Note: drooling starts at 3–4 months (when the salivary glands mature) and is NOT always a sign of teething at this age
- Fussiness and irritability — the pressure of teeth pushing through the gum is uncomfortable. About two-thirds of teething babies show increased fussiness, but it should be mild enough to soothe
- Swollen, red, or puffy gums — you may see a small white or bluish bump under the gum where the tooth is about to break through
- Constant gnawing, biting, and chewing — counter-pressure on the gums temporarily relieves teething discomfort, which is why babies chew everything they can find
- Ear rubbing on the same side as the erupting tooth — pain from the gums can radiate upward toward the ear; this is different from an ear infection — see below
- Facial rash around the mouth and chin — caused by constant contact with excess drool; this is purely a skin reaction to moisture, not an infectious rash
- Slightly elevated temperature — some studies show a very minor temperature rise in the hours around tooth eruption, but never reaching 100.4°F (38°C), which is the threshold for true fever
- Waking more at night — gum discomfort can disrupt sleep, especially around the eruption of larger teeth like molars
- Reduced appetite for solid foods — chewing on solid food increases gum pressure; babies may prefer softer foods or liquids while teething
Illness symptoms — what teething does NOT cause
This is the most important section of this guide. The following symptoms are not caused by teething, despite being widely and incorrectly attributed to it. If your baby has any of these, there is another cause that needs to be found:
- True fever (100.4°F / 38°C or above) — multiple large studies have confirmed teething does not cause fever. Any temperature at or above this threshold has an infectious or inflammatory cause
- Diarrhoea — teething does not cause diarrhoea. Despite being one of the most widely believed teething myths, there is no credible scientific evidence to support it
- Vomiting — not a teething symptom. Vomiting indicates a gastrointestinal infection or other illness
- Runny nose and nasal congestion — not caused by teething; indicates a viral upper respiratory infection (the common cold)
- Persistent cough — teething can occasionally cause a mild, occasional cough from excess drool running down the throat, but a persistent or worsening cough indicates respiratory illness
- Rash on the body (trunk, arms, legs) — a drool rash from teething affects only the face, chin, and neck. Any rash spreading to the body indicates a viral or bacterial illness
- Eye discharge or conjunctivitis — not a teething symptom; indicates infection
- Refusal to drink liquids — a baby who refuses even breast milk or a bottle is sick, not just teething
- Extreme, inconsolable crying — teething discomfort is mild and soothed relatively easily. A baby who cannot be consoled despite all usual comfort measures is in more significant pain that warrants medical assessment
Teething vs illness — side-by-side comparison guide
Use this comparison table as a quick reference whenever you are trying to decide whether your baby’s symptoms are from teething or from an illness:
| Symptom | 🦷 Teething | 🤒 Illness |
|---|---|---|
| Drooling | ✅ Very common — increased saliva production is a hallmark of teething | Rarely; drooling from illness is unusual in this age group |
| Gum swelling / redness | ✅ Yes — can see a raised white/bluish bump where tooth is erupting | Not typical; gums are usually normal in illness |
| Fussiness | Mild — usually soothed by chewing, cold, or comfort | Often more severe — inconsolable crying suggests illness |
| Temperature | Very mild rise — stays below 100.4°F (38°C) | ❌ True fever (≥100.4°F) is NOT teething — it means illness |
| Runny nose | ❌ Not caused by teething — indicates a cold or viral infection | ✅ Very common with upper respiratory infections |
| Diarrhoea | ❌ Not caused by teething despite the common myth | ✅ Classic sign of viral gastroenteritis or bacterial infection |
| Vomiting | ❌ Not a teething symptom | ✅ Indicates gastrointestinal illness |
| Cough | Occasional mild cough from excess drool — very mild and brief only | ✅ Persistent or worsening cough = respiratory illness |
| Rash | Drool rash only — limited to face, chin, neck from saliva irritation | ✅ Body rash (trunk, arms, legs) = illness such as roseola, hand-foot-mouth, etc. |
| Ear pulling | Possible — referred pain from gum can radiate toward ear | ✅ With fever or persistent pulling = ear infection |
| Duration | Short — symptoms are most intense in the 8 days around a tooth eruption | Varies — most viral illnesses last 3–7 days; bacterial illnesses need treatment |
| Appetite for liquids | May reduce for solids — but still takes breast milk or bottle normally | ✅ Refusing all liquids including milk or formula = illness and possible dehydration |
Specific scenarios parents confuse most often
Teething vs fever — the truth
No. Teething does not cause a true fever. This is one of the most widespread parenting myths globally — and it has been thoroughly investigated and debunked by medical research. A large Brazilian study tracking babies daily for 8 months found that temperatures increased very slightly on the day of and the day before tooth eruption — but never reached the 100.4°F (38°C) threshold that defines a fever.
What teething may cause is a very minor temperature elevation — perhaps sitting at 99–100.3°F. This is NOT a fever and does not require treatment. Any temperature of 100.4°F or above in a teething baby has another cause — most commonly a viral infection — and should be taken seriously.
Parents who attribute a genuine fever to teething may delay seeking care for a real infection — including ear infections, urinary tract infections, pneumonia, or in rare cases meningitis. Never dismiss a fever in a baby as “just teething.” Always treat fever and teething as separate issues and investigate the fever independently.
Teething vs diarrhoea
No. Teething does not cause diarrhoea. Multiple studies and the American Academy of Pediatrics, the NHS, and the WHO all agree: there is no credible evidence that teething causes loose stools or diarrhoea. The myth likely persists because babies teethe for most of their first two years — a period when viral gastroenteritis is also extremely common — so the two frequently coincide by chance.
If your teething baby has diarrhoea, they have picked up a viral or bacterial infection at the same time. The teething did not cause it. Treat the diarrhoea as a separate condition — prioritise hydration and watch for signs of dehydration.
Teething vs ear infection
Both teething and ear infections can cause babies to pull, tug, or rub at their ears — making this one of the most commonly confused presentations. Here is how to tell them apart:
Teething ear pulling: caused by referred pain from the gums radiating toward the jaw and ear. The baby will also be drooling, gnawing on things, and showing other teething signs. The ear pulling is occasional and mild, and the baby is relatively easily soothed. There is no fever above 100.4°F.
Ear infection ear pulling: more intense, persistent, and focused on one ear. Often follows a cold or upper respiratory infection. The baby will frequently have a true fever, be more distressed than expected, and may scream when lying flat (lying down increases pressure in the ear). Feeding may be more painful (swallowing changes ear pressure).
Teething vs common cold
A runny nose is NOT a teething symptom — full stop. If your baby has a runny nose while teething, they have caught a cold at the same time. This happens very frequently because teething begins at exactly the age when the maternal immunity passed through the placenta starts to wear off, making babies more susceptible to catching viruses for the first time.
A cold typically also brings nasal congestion, sneezing, mild fever, and a persistent cough — none of which teething causes. If your baby’s runny nose and fussiness resolve within the 8-day teething window and the tooth appears, the cold may have cleared. If symptoms persist well beyond a tooth eruption, the cold is the dominant issue.
Teething vs illness rash
Teething causes one specific type of rash — a drool rash. This is a red, irritated, sometimes chapped area of skin around the mouth, chin, cheeks, and neck caused by constant contact with excess saliva. It is not infectious, does not spread, and is managed with a barrier cream and keeping the area dry.
An illness rash is very different. Rashes from viral illnesses spread beyond the face — they appear on the trunk, arms, back, or legs. Roseola causes a distinctive pink rash that spreads from the trunk. Hand-foot-and-mouth disease causes spots in the mouth and on the hands and feet. Chickenpox spreads as small blisters across the whole body. Any rash that appears on the body beyond the chin and neck area during teething is caused by an illness and should be assessed by a doctor.
Why teething and illness happen at the same time
If teething does not cause colds, diarrhoea, or fever — why do so many babies seem to get ill exactly when they are teething? There are two very good reasons:
- Timing overlap with immune vulnerability — teething typically begins at 4–7 months, which is precisely when the immunity a baby received from its mother via the placenta starts to decline. As maternal antibodies fade and the baby’s own immune system is still maturing, babies become significantly more susceptible to catching viruses for the first time. The result: babies are teething AND getting ill with far more frequency at the same time, purely by coincidence of developmental timing.
- Putting everything in their mouth — teething babies explore their world with their mouths at a dramatically increased rate. Every toy, surface, hand, and object that enters their mouth is a potential vehicle for bacteria and viruses. A teething baby who is mouthing everything constantly is simply being exposed to more germs than a non-teething baby — not because teething causes illness, but because the behaviour that accompanies teething increases germ exposure.
Teething and illness frequently co-exist, but teething does not cause illness. Think of them as two separate events happening at the same time for developmental and environmental reasons. This distinction matters because it means that when your teething baby also has a fever of 102°F, the fever needs to be investigated and treated on its own merits — not dismissed as part of teething.
Safe teething relief — what actually works
When your baby is genuinely uncomfortable from teething, there are several evidence-based, safe methods to provide relief. The goal is to apply gentle counter-pressure or cooling to the gums to soothe the discomfort temporarily:
Wipe your baby’s chin and neck gently but frequently throughout the day to remove excess saliva. Apply a thin layer of barrier cream (petroleum jelly or zinc oxide cream) to the chin, cheeks, and neck before sleep and after feeds to protect the skin. Use bibs to absorb drool and change them frequently. Avoid rubbing the area roughly — gentle patting is much kinder to already-irritated skin.
Products and remedies to NEVER use for teething
Some teething products and traditional remedies are not just unhelpful — they are genuinely dangerous. Every parent should know these:
Frequently asked questions about teething vs illness
No. Teething may cause a very minor temperature elevation — sitting perhaps at 99–100.3°F (37.2–37.9°C) — but it does not cause a true fever of 100.4°F (38°C) or above. This has been confirmed by multiple large studies. Any temperature at or above the fever threshold in a teething baby has another cause and should be evaluated as a fever, not dismissed as teething.
No. Despite being one of the most persistent parenting beliefs worldwide, there is no scientific evidence that teething causes diarrhoea. Babies teethe for most of their first two to three years — a period when they also catch many gastrointestinal viruses for the first time — so the two frequently appear to coincide. But teething itself does not cause loose stools. If your teething baby has diarrhoea, they have a separate gastrointestinal illness that needs to be managed independently.
Both can cause ear pulling, but there are key differences. Teething ear pulling is occasional and mild, accompanied by drooling and gnawing, and there is no true fever. Ear infection ear pulling is more persistent and intense, often focused on one ear, frequently follows a cold, and is usually accompanied by a genuine fever above 100.4°F. The baby may also be more distressed when lying flat and may feed more reluctantly. If you are unsure, see a doctor — only an examination with an otoscope can confirm an ear infection.
No — a runny nose is not a teething symptom. If your baby has a runny nose while teething, they have caught a viral cold at the same time. This is extremely common because teething coincides with the age at which maternal immunity wanes and babies begin catching viruses. Treat the cold separately — keep the baby comfortable, ensure they drink plenty of fluids, and see a doctor if they develop a fever above 100.4°F, difficulty breathing, or seem more unwell than a typical cold would explain.
Research indicates that significant teething discomfort is confined to an 8-day window: the 4 days before a tooth emerges, the day of eruption, and the 3 days that follow. If your baby has been uncomfortable and unsettled for weeks or longer without a tooth appearing, something other than teething is very likely causing the distress. Over the full teething period (from first tooth to second molars), children go through this process intermittently for around 2–2.5 years — but the discomfort comes in short bursts around each individual eruption.
No. Amber teething necklaces are a genuine safety hazard — they pose a strangulation and choking risk and have been associated with infant deaths. There is also no reliable scientific evidence that they relieve teething pain in any meaningful way. Every major paediatric, dental, and child safety organisation worldwide advises against their use. Do not use amber necklaces or any jewellery on babies or toddlers.
The American Academy of Pediatric Dentistry (AAPD) and most paediatric dental organisations recommend that a baby’s first dental visit should occur by their first birthday — or within 6 months of the first tooth appearing, whichever comes first. This early visit allows the dentist to check that teeth are developing normally, give guidance on dental hygiene, and establish a relationship with the child before anxiety develops around dental visits.
Yes — infant ibuprofen is safe and effective for teething pain in babies over 6 months of age. It has the added benefit of being an anti-inflammatory as well as a painkiller, which addresses the gum inflammation that causes teething discomfort. Always use the infant formulation and calculate the dose based on your baby’s weight, not age. For babies under 6 months, infant paracetamol (acetaminophen) is the safe option — ibuprofen is not approved for this age group. Never give aspirin to babies or children.
When to call the doctor
• Has a temperature of 100.4°F (38°C) or above — this is a true fever and is not from teething
• Is under 3 months old with any fever — always a medical emergency
• Has a rash spreading beyond the face and neck to the trunk, arms, or legs
• Is vomiting repeatedly or has significant diarrhoea
• Is inconsolable and cannot be soothed by any comfort measure
• Is refusing all liquids — breast milk, formula, or water
• Shows signs of dehydration — no tears, dark urine, very dry mouth
• Has persistent, intense ear pulling with fever or after a recent cold
• Has a non-fading rash — press a glass to it; if it does not fade, call emergency services immediately
• Has had symptoms for more than a week without a tooth appearing
• Has had no teeth by 12–18 months — worth a routine review to check dental development
• Has a persistent runny nose for more than 10–14 days — could indicate sinusitis or an allergy
• Seems to be in more than mild pain that is not relieved by any of the safe teething methods
• Has visible pus or discharge around a tooth — could indicate infection
• Is pulling at one ear specifically and also seems unwell in other ways
Final thoughts
The teething vs illness question is genuinely one of the trickiest parts of parenting a baby — partly because the two often happen at the same time, and partly because there is so much well-meaning but medically inaccurate advice passed down through generations. Teething is real, uncomfortable, and worthy of attention and comfort. But it is a localised, gum-based process — it does not reach into the gut, the lungs, or the ears.
The simplest rule to remember is this: if it is a teething symptom, it involves the gums and the mouth. Drooling, gnawing, swollen gums, fussiness, and mild gum discomfort are teething. Everything else — fever, diarrhoea, vomiting, runny nose, rash on the body, or a baby who cannot be comforted — deserves its own investigation as a separate illness.
Trust your instincts as a parent. You know your baby’s normal. When something feels beyond the usual teething fussiness, it probably is — and calling your paediatrician is always the right thing to do when in doubt.
“Teething is uncomfortable — but it is not sickness. Know the difference, and you will always know when to act.”