Teething is a normal stage in a child's development, but it is one of the stages surrounded by the most folklore. Fever, diarrhoea, disturbed sleep, crying, even a runny nose are frequently blamed on teething — yet appearing in the same period does not mean the teeth are the cause.
When does teething start?
For most babies the first tooth appears during the first year, usually around 6 months, but the natural variation between babies is wide: for some it comes before 4 months, for others after the first birthday.
The front incisors are usually the first to appear, and the baby teeth continue coming through gradually until roughly two to three years of age.
So a first tooth arriving later than another baby's does not, in itself, indicate a problem.
What symptoms may come with teething?
Teething can pass with no clear symptoms at all, and when symptoms do appear they are usually mild and short-lived.
Among the things you may notice:
More drooling
Drooling may become more noticeable during this period.
Wanting to bite and chew
The baby looks for things to put in their mouth and press against the gums; that pressure may ease the discomfort.
Tender or slightly swollen gums
The area where the tooth is coming through may look redder or more sensitive.
Mild fussiness or irritability
The baby may be more restless than usual for a short while around the tooth's arrival.
Skin irritation around the mouth
Extra saliva in constant contact with the skin can cause redness or a mild rash around the mouth and chin.
What about fever?
One of the most widespread beliefs is that teething causes fever.
Teething may coincide with a slight rise in body temperature within the normal range, but the evidence does not support treating teething as a cause of genuine fever.
So if a baby's temperature reaches 38°C or higher, it is better not to explain it away as "just the teeth" — especially alongside other symptoms, or when the baby seems unwell.
This matters: attributing a fever to teething can delay finding another cause, such as a viral or bacterial infection.
Does teething cause diarrhoea?
There is no good evidence that teething causes diarrhoea.
Diarrhoea may coincide with teething, but coinciding does not mean one caused the other. Repeated or persistent diarrhoea — especially with vomiting, fever, reduced urine output or signs of dehydration — needs assessment based on the baby's age and condition.
Likewise, a runny nose, frequent illness or hard crying should not be read automatically as teething.
How to ease teething discomfort
In most cases no treatment is needed, and simple, safe measures are enough:
- Gently massage the gums with a clean finger.
- Offer a teether suited to the baby's age.
- A teether can be cooled in the fridge, but freezing it until it is rock hard is not advised.
- If the baby is in clear pain, ask your doctor whether a pain reliever suited to their age and weight is needed.
Teething gels containing benzocaine are not recommended for babies, and the American Academy of Pediatrics does not recommend amber necklaces or teething necklaces: there is no evidence they work, while they carry a risk of choking or strangulation.
When not to say "it must be the teeth"
If the baby has a genuine fever, persistent diarrhoea, vomiting, marked lethargy, severe or unusual crying, difficulty breathing, reduced feeding or drinking, or simply seems unwell, it is important not to assume teething is the cause, and to assess the situation by the baby's age and accompanying symptoms.
In short
Teething is a normal stage, and its symptoms are usually limited: more drooling, wanting to chew, tender gums and mild discomfort.
Genuine fever, diarrhoea, hard crying or clear signs of illness should not be counted as a normal part of teething.
A tooth on its way through does not mean that everything happening to your baby in that period comes from it.