If you're wondering why babies sweat so much when they sleep, here's some useful information for you.

So your nighttime routine is all done – baby had her bath, is nice and warm in her pyjamas, you’ve turned on the aircon and she falls asleep after nursing and listening to the soothing lullabies that you sing. You creep out of the room and return after an hour just to check, and you find your baby sweating while sleeping. This happens all the time and you cannot for the life of you understand just why this happens.

Mums and dads, especially if this is your first baby, we completely understand that something as seemingly innocuous as your baby’s sweat, could get you all worried and maybe even making an appointment with your paediatrician.

So before you do that, we are here to provide you with some basic information that you need to know. 

The good news is that in most cases, the infamous wet patch behind your baby’s head, that you often find when she is fast asleep, is really nothing to worry about. Here are some possible reasons behind it.

What is the nervous system? It is a complex network of nerves and cells that carry messages to and from the brain and spinal cord to other parts of the body. Our nervous system also controls our body temperature.

However, the nervous system of newborn babies isn’t fully developed yet. Consequently, the nervous system isn’t able to regulate the body temperature of a newborn the way it does for adults. And this explains babies sweating while sleeping. 

What are night sweats? Night sweats refer to excessive perspiration by infants and children, especially when they are sleeping. In other words, that infamous wet patch that you often find on your baby’s pillow, or where she rests her head while sleeping.

As adults, our sweat glands aren’t confined to one part of our body. But babies are different. They don’t have as much sweat glands in their armpits and their most active sweat glands are located on their heads. This causes them to sweat excessively, particularly at night when they don’t change their head position much. 

So the lack of movement in addition to the sweat glands on the head explains your baby sweating while sleeping, and that wet patch she leaves behind!

Yes, it’s really as simple as that. Most of time we sweat because we feel warm. Likewise, a simple and obvious reason your baby is sweating while sleeping is that the room is too warm, or they are too warm. Some parents like to dress their babies in thick, fleece sleep suits that cover them from head to toe. In addition, they swaddle the baby and place blankets, comforters or quilts over them. 

Well mums and dads, I don’t think I need to remind you just how hot the weather is here in Singapore. So go easy on the sleepwear. I know how irresistibly cute some pyjamas are, but do spare a thought for the most important thing – your baby’s comfort!

As mentioned earlier, most of the time, a baby sweating while sleeping is normal and nothing to worry about. But these are some conditions that the excessive perspiration could be an indication of:

Apart from your baby sweating while sleeping, if you find her sweating excessively during simple activities such as feeding, it’s probably time to make an appointment with the paediatrician as it is a symptom of a congenital heart problem.

A congenital heart problem is a result of defective development of the heart in the foetus. Babies with this condition end up sweating much more than other babies because their heart has to work so much harder to pump blood efficiently. 

If you find that even in a cold, air conditioned room, your baby still sweats profusely, it could be attributed to a condition known as hyperhidrosis. 

Hyperhidrosis is when a baby is sweating beyond what is required of the body to maintain normal body temperature. It’s common for people with sweaty palms and feet to have this condition as well. 

This is not something that you particularly need to treat with medication. It’s nothing serious really, contrary to what it sounds like. Rather, as the child gets older, you can teach them sweat management techniques such as using antiperspirants.

Found more commonly in premature babies, sleep apnea is another reason for babies to sweat in their sleep. It is also accompanied by bluish skin colour, wheezing sounds and pauses of up to 20 seconds while breathing, and that causes the baby’s body to work really hard to breathe. 

Many people overlook the danger of overheating a baby. This causes the them to fall into a very deep sleep that is difficult to wake up from and can result in SIDS.