Teething causes high fever
Teething can cause a slight rise in body temperature, irritability, and drooling, but it does not cause a true fever of 38 degrees Celsius (100.4 Fahrenheit) or higher. Any fever reaching that threshold in an infant reflects illness, not teething, and needs medical evaluation.
What we know
Teething, the eruption of primary teeth through an infant's gums typically beginning around six months of age, is genuinely associated with several uncomfortable but minor symptoms: increased drooling, gum irritation and swelling, a mild urge to chew or bite on objects, disrupted sleep, and occasionally a modest, low-grade elevation in temperature. Where the popular belief goes wrong is extending this modest temperature bump into the claim that teething causes a true fever, defined clinically as a body temperature of 38 degrees Celsius (100.4 Fahrenheit) or higher.
A frequently cited prospective study followed infants through the eruption of their teeth and found that temperature elevations associated with teething, when they occurred at all, remained below the clinical fever threshold and typically did not exceed about 37.4 to 37.8 degrees Celsius. The proposed biological mechanism behind this minor rise involves mild, localized inflammation in the gum tissue as the tooth erupts through it, which can produce a small systemic inflammatory response, but this process is limited in scope and does not trigger the same immune cascade that produces a genuine fever in response to infection.
The American Academy of Pediatrics states directly that teething does not cause high fever, seizures, diarrhea, or the significant symptoms sometimes attributed to it by tradition, and that these more serious symptoms, when they occur in a teething-age infant, should be attributed to a separate cause, most often a concurrent viral or bacterial illness, and investigated as such. This is an important clinical distinction with real consequences: infants are teething on and off for roughly two years, a period during which they are also naturally exposed to a large number of common childhood infections, including colds, ear infections, and stomach viruses, particularly once they begin daycare or more social contact with other children. Because teething and minor illness frequently coincide simply due to overlapping timing, parents and even some clinicians have historically misattributed illness-driven fevers to teething, a phenomenon that has been studied and documented as a recognized diagnostic pitfall in pediatric practice.
This misattribution carries genuine risk, which is the main reason pediatric bodies push back firmly against the myth. If a parent assumes a true fever is "just teething" and does not seek appropriate medical evaluation, a real underlying infection, which in young infants can escalate quickly, may go undiagnosed and untreated for longer than it should. The American Academy of Pediatrics and similar bodies in the UK and elsewhere consistently advise that any fever of 38 degrees Celsius or higher in an infant, especially one under three months old, warrants prompt medical attention regardless of whether the infant happens to be teething at the time.
Appropriate management of genuine teething discomfort includes offering a clean, chilled (not frozen) teething ring or a cold, wet washcloth for the infant to chew, gently massaging the gums with a clean finger, and using infant acetaminophen or ibuprofen at appropriate weight-based doses if discomfort is significant, following a pediatrician's guidance. Topical teething gels containing benzocaine are specifically discouraged by the U.S. Food and Drug Administration due to a rare but serious risk of methemoglobinemia, a blood disorder that reduces the blood's oxygen-carrying capacity, in infants and young children.
Common claims
- Teething causes high fever in infants.Not supported
- Teething can cause a mild temperature increase.Accurate
- A fever of 38C or higher in a teething infant is normal.Not supported
- Teething causes diarrhea and seizures.Not supported