How Sensory Processing Affects Sleep in Highly Sensitive Children
One reason highly sensitive children (HSC) struggle with falling asleep is often because their nervous system is still trying to process the day. HSC have, what is known as sensory processing sensitivity. This is a biological trait that results in a sensitive nervous system which causes HSC to process sensory information more intensely.
Most of us are familiar with 5 senses: sight, hearing, taste, touch and smell but there is also vestibular, tactile, proprioceptive and interoception. How HSC process and register information from each sense can impact their sleep quality. It is helpful to learn which affects your child and ways to manage the input to help support sleep.
Highly sensitive children may process input differently across multiple senses, each of which can affect sleep in its own way. Let’s dive deeper into the senses:
Sight
Visual input like bright lights and screen time can prevent the nervous system from shifting into the parasympathetic state needed to be able to sleep. This is not to say that all screen time will affect sleep, but the type, duration and timing can affect HSC more so than non-HSC. Dimming lights and avoiding screens 1–2 hours before sleep can help in most cases.
Hearing
Auditory input like sounds including volume, pitch and background noise. Non-HSC can block out low level noise and sleep well whereas HSC may struggle with even the softest noises. White noise machines have been recommended in the sleep world regularly to help block out noises however for some HSC it can add to the noise and contribute to night wakings. Lowering the volume and/or looking for different sounds may help. If you wish to use a sound machine, keep it as far from the child’s head as possible and no more than 40–50 decibels.
Taste
Input includes flavors, textures, and temperature of food. Eating challenges that are a result of sensory sensitivities can lead to nutrient gaps that affect sleep. Hunger can also play a role depending on the child’s food preferences. They may be eating enough volume, but it may not be nutrient dense enough to be able to carry them through the night. On the other hand, if you have a very active child and an early dinner then they may get hungry in the middle of the night. A balanced bedtime snack consisting of protein, complex carbohydrates and healthy fats can help keep tummies full through the night.
Tactile
Input includes texture, pressure and temperature on skin. Tactile is different from touch in that touch refers to the physical sensation of skin contact whereas tactile is how the nervous system processes and interprets that input. Tactile sensitivity is the strongest predictor of sleep challenges (and also linked to eating challenges). Cutting off tags in pyjamas, purchasing soft pajamas, pillowcases, blankets and sheets can help HSC relax physically in bed. Listening to the child here is helpful, as they may really need it to be addressed to be able to sleep.
Smell
Input includes odor, scents and aromas. Strong scents from soap, detergent, dryer sheets, perfumes, linen sprays, plug in deodorizers, or food smells can overwhelm the child and affect their ability to sleep.
Vestibular
This system senses balance, motion and where the body is/moves in space. HSC may find certain types of movement too close to bedtime to be overwhelming while under-stimulated HSC will need more activity. General sleep advice is to reduce movement before bedtime and have a calm relaxed period before the bedtime routine. For HSC that have been under stimulated throughout their day, they may search for more movement because their nervous system needs it. This is often misunderstood and seen as stalling, misbehaviour or not being tired enough to go to sleep.
Proprioceptive
This system senses position, movement and muscle effort. HSC who are under stimulated in their day may seek out active play, roughhousing, moving heavier objects by lifting, pulling or pushing to feel grounded. Encourage this movement (but not super close to bedtime), as it will help the child feel less restless in bed and support sleep.
Interoception
This sense is about detecting internal bodily signals including hunger, thirst, body temperature, needing to use the bathroom, internal tension and tiredness. Some HSC may struggle with recognizing these internal signals making them less aware of what their body needs while others may become more aware of these signals and both can affect sleep. It is possible for HSC to have heightened awareness of some sensations (like discomfort) and not recognize others (like the need for sleep). Understand your child’s sensory profile and learning ways to directly support them will help optimize their sleep.
Sensory Overload and Its Impact on Sleep
Sensory overload happens when one is exposed to more sensory input than they can comfortably process. It can be the multiple senses are being stimulated at the same time or one of the senses is overwhelmed. HSC are not necessarily sensitive in each of the sensory systems; they can be extremely sensitive in one or two and then average in the others. Also, HSC can be sensory seekers (actively pursue stimulation like climbing and jumping) in certain areas while being avoidant (easily overwhelmed by input) in others.
Sleep challenges can stem from a mismatch between the sensory needs and the environment – too much or too little stimulation. For sensory seekers, they tend to benefit from movement and sensory rich activities to help them feel regulated and calm for sleep. Sensory avoiders tend to do well with calm, predictable routines and low stimulation to help them regulate for sleep. Bath before bedtime can be calming or overstimulating depending on the child. Knowing what overstimulates your child will help decide what is the best bedtime routine.
Though not the only factor at play, sensory processing is a factor in sleep struggles for highly sensitive children. When sensory needs are misunderstood or unmet, the nervous system remains on high alert—making sleep harder to access. Some families find it beneficial to work closely with an occupational therapist to support their child. Understanding what inputs your child needs, creating supportive bedtime routines, and working on any eating challenges can help support their sleep and overall wellbeing.