why do babies sleep with their mouth open



Why Do Babies Sleep With Their Mouth Open?

It can be quite alarming to see a baby sleeping with its mouth open, but is it dangerous or is there a reasonable explanation as to why this happens? Fortunately, the answer is often due to the way babies breathe when they are in a deep sleep.

The Science of Baby Sleep

Babies in a deep sleep often breathe through their mouths because their bodies don’t yet know how to regulate their temperature whilst asleep.

There are three ways that babies can sweat:

    • Through their skin


    • Evaporative sweating


    • By breathing out moist air


Due to their immature bodies, babies often perspire more than adults when asleep, so their mouths open in order to expel any extra moisture. This also helps them to keep cool during a deep sleep, which is essential for getting restful sleep.

Other Reasons

In some cases, a baby may suffer with a blocked nose due to a cold or allergy, meaning they cannot breathe through their nose and therefore have to open their mouth to get the air they need. Additionally, they may have a tongue tie which prevents them from properly closing their mouth, or they may even have a medical condition such as reflux or a sleep disorder.

What Parents Should Do?

Sometimes babies will stop breathing, or take shallow breaths, when asleep with their mouth open, but this tends to be short, brief pauses and is usually normal for a baby.

However, if you are worried about your baby’s breathing, it is always best to look for signs of distress or an underlying health issue. These can include:

    • Changes in their level of activity during the day


    • Difficulty feeding and fussiness


    • A bluish colour in the skin, especially around their face and lips


If you are concerned, it is important to speak to your health care provider for advice and to rule out any medical conditions or allergies.

In most cases, babies sleeping with their mouths open is not something to be overly concerned about. However, it is always a good idea to get medical advice if you have any worries.