One of the most common reasons a mother brings her child to me is because of their sleep - or lack thereof. Often said mother has probably been to a thousand other practitioners, in every facebook group, seen a few sleep consultants, and is still deprived of her sleep. And this isn’t just for babies. I see many toddlers, kids and teenagers who also have trouble sleeping. Sometimes, the vagus nerve is involved, and in this blog we are going to cover why.

What is the vagus nerve?

If you have been following me a while, you probably know more about the vagus nerve than your average Joe. But let’s assume that you’ve stumbled upon this blog and you’re hearing this information for the first time!

The vagus nerve is the longest cranial nerve in the body, stretching all the way from your brain stem, through your neck, chest, abdominal organs and all the way to your pelvic floor. It is part of the parasympathetic nervous system, which is also known as “rest and digest”, or the part of the nervous system that helps you feel calm and regulated. [Before motherhood overwhelmed and exhausted you!].

This is the opposite of the “fight and flight” system, also known as the sympathetic nervous system. However, when the vagus nerve is either 1. detecting a threat, or 2. not functioning well.. the result is the fight or flight system is activated (maybe more than it should be).

The vagus nerve tells your brain and body “you are safe”.

How does the parasympathetic nervous system relate to sleep?

Activation of the parasympathetic nervous system is required for QUALITY sleep, which is really the depth with which we can fall into sleep. The reason that the vagus nerve is included within this scope is because we not only need sleep hormones to help us sleep, but we need a sense of SAFETY above all else. And guess what tells us whether we are safe or not? Well that would be the vagus nerve!

One of the sleep hormones - melatonin - is only released when the parasympathetics are working properly. This is why when you’re stressed or worried about something, you sleep less. Melatonin helps us fall asleep, so sometimes if the vagus nerve is underactive, or low tone, you might fall asleep just fine but wake up constantly during the night. (Melatonin is also largely impacted by blue light exposure, which is why its best to turn off all blue lights at least 2 hours before bedtime).

Why do you need to feel safe to sleep?

Our nervous systems are quite primitive (though we like to think they aren’t!). And the first ‘question’ our vagus asks itself is “Am I safe?”.

Sleep is one of the most vulnerable positions we can put ourselves in, because it’s impossible to activate our fight or flight mechanisms while we are snoozing away. Imagine being out in the wildnerness trying to have a nap, wondering if it’s a good time to sleep, wondering if you’re safe enough to not get eaten while you sleep. Our nervous systems are still doing this! It happens completely subconsciously, and so quickly that we aren’t even aware of it. Yet it can guide something as powerful as whether we can dip into a deep sleep, or sleep with “one eye open”.

The sympathetic nervous system keeps us awake

If your child’s nervous system is not receiving safety cues, it makes sense that your child will stay awake. Even if you will them to sleep!

This is because it is safer, and more protective, for them to be awake. They can defend themselves, or seek safety in their caregiver (hello cosleeping and feeding allllllll night long). The danger for them is in falling asleep.

Or possibly they fall asleep ok, but wake constantly through the night to check you’re there.. can you see how they are seeking your safety, because for whatever reason their nervous system doesn’t feel safe enough in their own body?

The sympathetic nervous system is the “fight or flight”. When it is overactive, in a child this can look like a wired child who just won’t wind down, a child who has a ten minute nap then PING is wide awake like they’ve slept all night, or a child who constantly wakes overnight.

The sympathetic and parasympathetics are kind of like a seesaw, so they don’t work in isolation. And they communicate with other areas of the brain to really drive behaviour. But in essence when the sympathetics are high, the parasympathetics are low and vice versa.

The vagus nerve and sleep

If your child’s vagus nerve is low tone, ie it isn’t working well, then your child will feel less safe in general. This might look like a lot of safety cues to get them to sleep. Perhaps cosleeping, or lots of rocking them, lots of contact, breastfeeding to sleep.. you get the idea. However your child feels safe will be how they seek out their sleep.

Now if you then place them in their room (or even if you cosleep), if their vagus nerve is low tone and they wake up again during the night, their nervous system is going to tell them they are not safe again. So they are going to require high levels of safety cues to fall back asleep again, and it might take even MORE than the first sleep of the night, because now it is dark, and scary, and they have been shocked into wakefulness by their own nervous system.

Vagal tone

Vagal tone basically refers to the ‘strength’ of the vagus nerve. How well it works. Our vagal tone is largely influenced during our womb life and early childhood, though it can be impacted through traumas and life experiences as well.

It’s job is to tell the rest of the brain whether you’re safe or not - not only to sleep, but to engage with other people, to get around during your day, to complete tasks, and more. The vagus nerve drives a lot of our subconscious behaviours, and contributes to how often our fight or flight response is activated.

A vagus nerve with lower tone has less ability for safety - lending the nervous system to detect everything as a threat.

A vagus nerve with higher tone will have more ability to regulate, feel safe in their body and in the environment, and usually it takes a lot more of a threat to activate the fight or flight.

Having optimal vagal tone will support your child in falling asleep, staying asleep, and waking up happy!

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