Teething vs Illness: How to Tell the Difference

A Primary Health Care Nurse’s Guide for Worried Parents

Parents become anxious when their baby suddenly becomes fussy, clingy, or refuses feeds. One of the most common concerns I hear from parents in the clinic is, “Is this just teething, or is my baby getting sick?”

As a primary health care nurse and as a mother myself, I understand how difficult it can be to tell the difference. Teething and illness often happen around the same age, and many symptoms overlap. It’s easy to blame everything on teething, but sometimes there is something else going on.

The good news is that there are a few clues that can help you decide whether your little one is simply cutting a tooth or whether they need medical attention.

Teething vs Illness: The Quick Answer

Teething usually causes mild symptoms such as drooling, chewing on objects, swollen gums, mild fussiness, and temporary changes in sleep or appetite.

High fever, vomiting, diarrhoea, severe cough, difficulty breathing, unusual sleepiness, dehydration, or a baby who seems very unwell are not typical signs of teething and should not be ignored.

If your baby has a temperature of 38°C (100.4°F) or higher, it is safest to think about infection or illness rather than assuming teething is the cause.

Why Parents Often Confuse Teething With Illness

Teething commonly begins around six months of age. Coincidentally, this is also when babies start putting everything into their mouths, become more mobile, and are exposed to more viruses.

In my experience as a primary health care nurse, many parents are surprised to learn that teething itself does not cause high fevers, diarrhoea, vomiting, or severe illness. Teeth often get blamed simply because the timing overlaps.

What Are Normal Signs of Teething?

Most babies experience only mild symptoms. These can include:

• Increased drooling.
• Chewing on hands, toys, or anything within reach.
• Mild irritability.
• Swollen or tender gums.
• Wanting extra cuddles.
• Brief sleep disturbances.
• Temporary reduced interest in solids.

Some babies sail through teething with hardly any symptoms, while others become more unsettled for a few days before the tooth appears.

What Symptoms Suggest Illness Instead?

Symptoms that deserve closer attention include:

Fever

A mild rise in temperature may occur, but a true fever of 38°C or higher should not be blamed on teething.

Persistent Runny Nose and Cough

While teething can cause some extra drooling and a mild, clear runny nose, it does not cause a persistent cough or thick mucus. If your baby develops a lasting cough, wheezing, or trouble breathing, it’s more likely a cold or infection than teething, and it’s worth checking with your doctor.

Vomiting or Diarrhea

Many parents ask whether teething causes diarrhoea.

Current evidence shows that severe diarrhoea and vomiting are not caused by teething. A stomach bug or another infection is much more likely.

Severe Fussiness

Teething discomfort usually improves with cuddles and comfort.

If your baby cries inconsolably, seems floppy, is difficult to wake, or cannot be comforted, this is not typical teething behaviour.

Refusing Fluids

Babies with sore gums may temporarily eat less, but they should still drink and produce wet nappies.

Reduced urine output, dry mouth, no tears when crying, or sunken eyes are warning signs of dehydration and need urgent medical attention.

Teething vs Illness: A Simple Comparison

Signs More Likely Due to Teething

• Drooling.
• Chewing everything.
• Mild fussiness.
• Swollen gums.
• Brief sleep changes.
• Slight decrease in appetite.
• Symptoms last for a few days around the tooth eruption.

Signs More Likely Due to Illness

• Fever above 38°C.
• Vomiting.
• Diarrhoea.
• Persistent cough.
• Difficulty breathing.
• Rash all over the body.
• Severe lethargy.
• Poor feeding.
• Fewer wet nappies.
• Symptoms worsening instead of improving.

If you’re unsure when to take your baby to the hospital, read Clinic or Hospital for a Sick Baby? Emergency Warning Signs Parents Should Know

Can Teething Cause Fever?

This is probably the question I hear most often.

Research shows that teething may cause a slight increase in temperature, but it does not cause a true fever. If your baby’s temperature reaches 38°C or higher, it is important to look for another cause rather than assuming it’s “just teething”. If you’re worried about fever, you can read my article on Child Fever: What Is Normal and What Isn’t

Can Teething Cause Ear Pulling?

Yes, sometimes.

The nerves around the gums, jaw, and ears are connected, so babies who are teething may pull their ears.

However, ear pulling accompanied by fever, severe irritability, or crying when lying down may indicate an ear infection and should be assessed by a healthcare professional.

Can Teething Cause Poor Sleep?

Yes.

Some babies become restless or wake more often for a few nights while a tooth is erupting. However, prolonged sleep problems lasting weeks are unlikely to be caused by teething alone.

What Can Parents Do at Home?

Most teething discomfort can be managed with simple measures.

Offer a chilled teething ring or cool washcloth to chew on.

Gently massage your baby’s gums with a clean finger.

Continue breastfeeding or offering fluids regularly.

Provide extra cuddles and reassurance.

Keep drool away from the skin to prevent a rash around the mouth and chin.

Avoid amber teething necklaces because they pose choking and strangulation risks.

Avoid teething gels containing benzocaine or homoeopathic remedies unless specifically recommended by your healthcare provider.

When Should You Seek Medical Attention?

Contact your healthcare provider if your baby:

• Has a fever of 38°C or above.
• Refuses fluids.
• Produces fewer wet nappies.
• Vomits repeatedly.
• Has severe diarrhoea.
• Develops breathing difficulties.
• Appears unusually sleepy or difficult to wake.
• Has symptoms lasting longer than expected.
• Seems much sicker than “normal teething”.

For babies younger than three months with a fever, urgent medical assessment is recommended.

Frequently Asked Questions

How do I know if it’s teething or an ear infection?

Teething can sometimes cause ear pulling because the nerves in the jaw and ear area are connected. However, fever, severe pain, waking frequently at night, crying when lying down, or fluid draining from the ear suggest an ear infection rather than teething.

How long do teething symptoms last?

Most symptoms come and go over a few days and improve once the tooth breaks through.

Can teething cause a runny nose?

Drooling may cause mild, clear mucus, but a thick, runny nose, congestion, and cough are more suggestive of a cold.

Can teething cause diarrhoea?

No. Persistent diarrhoea should not be blamed on teething.

Absolutely. Teething and illness can occur at the same time, which is why it’s important not to assume that teething is the cause of every symptom.

Is loss of appetite normal during teething?

A temporary reduction in solids intake is common, but babies should continue to take fluids and produce wet nappies. If you’re concerned about feeding, read my full guide on Baby Not Feeding Well: What It Really Means and When to Worry.

A Word From Nurse K

One of the biggest mistakes I see is parents feeling reassured by the phrase, “It’s probably just teething.”

Sometimes it is.

But sometimes babies are genuinely unwell, and symptoms such as fever, vomiting, breathing difficulties, severe lethargy, or dehydration deserve prompt medical attention.

Trust your instincts. You know your baby best. If something doesn’t feel right, it’s always reasonable to seek advice.

If you found this post helpful, you might also like:

Can Teething Cause Fever? What Parents Need to Know

TEETHING IN BABIES: SYMPTOMS – WHAT’S NORMAL VS NOT

Teething and Breastfeeding: Why Babies Bite, Feed Less, and Refuse the Breast

Ear Pain in Children: Teething, Ear Infection, or Something Serious?