People often believe that teething can cause symptoms such as a runny nose, fever, pain, irritability, and sleep problems. However, the scientific evidence behind these beliefs is not straightforward.
Researchers have come to varied conclusions about the links between these symptoms and teething. While many experts agree that teething does not cause congestion or a runny nose, the stress involved with teething may make infants more susceptible to childhood illnesses.
In this article, we examine the links between teething and several symptoms, including a runny nose. We also describe what regularly occurs with teething, common causes of a runny nose in infants, and when to see a doctor.
An infant usually gets their first tooth at around 6 months. They tend to have a complete set of 20 teeth by 30 months.
The teething period for each tooth typically takes 8 days. It begins 4 days before the tooth comes through the gum and lasts for 3 days afterward. This process is known as tooth eruption.
Many parents and caregivers notice issues, such as a runny nose or a fever, before a new tooth arrives. But some experts believe that these symptoms are not directly related to teething.
However, some experts believe that there may be an indirect link and that the stress of teething may make infants more vulnerable to infections, which can cause symptoms such as a runny nose.
Between the ages of 6 and 30 months, the teeth come in, and the immune system changes. During this period, the protection that an infant was born with and may have received through breastmilk starts to decrease.
At the same time, babies are beginning to interact more with the wider world and are becoming increasingly exposed to childhood illnesses.
Infants also tend to chew on things during the teething process, and this can expose them to germs.
The main signals of teething are:
- a face rash, which occurs when drool contains small particles of food that irritate the skin
- an increased desire to chew on things
- mild gum pain, which can result from germs in the mouth getting into new breaks in the gums, and not all children feel it
Teething is unlikely to cause:
- excessive crying
- a high fever
- a loss of appetite for liquids
- disturbed sleep
- diarrhea or loose stools
The nose regularly produces mucus, a fluid that keeps the inside of the nose moist and traps germs before they penetrate further. The body usually sweeps mucus back into the throat and swallows it.
A runny nose, or rhinorrhea, happens when excess mucus flows through the nose rather than running down the throat.
Mucus can be thick or thin, and transparent or opaque. A runny nose will usually go away on its own.
Some causes of a runny nose in children include:
- Cold weather. This can trigger a reaction that causes the body to produce more mucus.
- Crying. Tears can pass through the nasal cavity and into the nose.
- Irritation. A runny nose can result from exposure to allergens or irritants, such as smoke and pollution.
- Colds and flu. These viral infections can cause the nasal cavity to fill with mucus, creating an obstruction that results in a runny nose.
- Obstruction. A foreign body can become lodged in the nose, with similar results.
- Sinus infection. The sinuses are the cavities in the face that drain into the nose. During an illness, these can fill with infected mucus, and the resulting congestion can cause the sinuses to become inflamed. However, the sinuses of an infant are not fully developed, and this type of infection is uncommon in babies.
- Adenoids infection. The adenoids are the tissue in the back of the nose. In children, an infection in this tissue can lead to a runny nose.
The following causes are less common:
- Choanal atresia. This occurs when bone or tissue closes off the back of the nose. If both sides are blocked, doctors usually detect it just after birth. However, if the atresia only affects one side, it may go undetected for a time.
- Pyriform aperture stenosis. This occurs when the bony nasal opening is so narrow that it obstructs the nose.
- Deviated nasal septum. The nasal septum is the wall of bone and cartilage that separates the two sides of the nose. In some cases, the septum can lean to one side and cause an obstruction. A person can be born with it, or it can result from an injury to the nose.
- Nasal polyps. These grape-like growths in the lining of the nose can cause the nose to run.
- Nasal cysts or tumors. In rare cases, these can cause obstructions. The growths can be cancerous, and they often only develop in one side of the nose.
A doctor should check any baby who is inconsolable or who has a high fever. These symptoms can occur with illnesses such as an ear infection.
If a runny nose does not go away, this can point to an underlying health issue, such as those listed above. If an infant's nose is runny for more than 10 days, they should receive medical attention.
People often attribute a runny nose and other symptoms to teething. However, there is no evidence that teething causes a runny nose, a fever, diarrhea, vomiting, or excessive crying. These symptoms more likely result from exposure to the wider world and childhood illnesses.
If a baby is inconsolable, has a fever, or has severe or persistent symptoms, see a doctor. Speak to a medical professional any time an infant's symptoms are concerning.