Sensory overload explained

Everything we experience and do involves our senses, sight, smell, hearing, taste, and touch. The term sensory processing refers to how the brain receives, organises, and makes sense of incoming stimuli through the senses. Sensory integration and processing is important in everything we need to do daily, each sensory system has its own unique role and together they inform our brain, then our brain decides how to react to the sensory information and interact with our environment, whether to ignore it, pay attention to it, or respond in a particular way.

There are some people who have difficulty processing information from their senses, and because of this difficulty processing information, it can lead to difficulties in responding appropriately to it. Estimates indicate that 5% to 16.5% of the general population have symptoms associated with sensory processing challenges and these estimates are higher for clinical populations such as autism spectrum disorder (ASD) and attention deficit hyperactivity disorder (ADHD).

Sensory processing difficulties include feeling overwhelmed by too much sensory input, this is known as sensory overload. In this article we explore sensory overload, its sign and triggers and look at prevention and coping strategies that can be implemented to help deal with the condition.

What is sensory overload?

For most people, the brain automatically filters out unnecessary sensory input and focuses on what is important. Sensory overload is when any one, or a combination of any of a person’s five senses, sight, sound, taste, touch, and smell, takes in more information than their brain can process, it struggles to interpret, prioritise, or filter out irrelevant sensory information, and becomes overwhelmed by too much sensory input or stimuli. The brain, perceiving the overwhelming input as a threat, can respond as it would to a life-threatening situation and activate the sympathetic nervous system, triggering the fight, flight, or freeze response which can lead to feelings of discomfort and distress that can range from mild to intense.

A great analogy for sensory overload is likening it to having too many tabs open on an internet browser; the operating system gets overwhelmed and just can’t keep up, slowing everything down. Possibly the screen freezes, or in severe cases “blue screen” occurs, this not necessarily fatal for a computer, but it does indicate a serious issue. Sensory overload is likened to a blue screen in computers because both scenarios describe a system failure where the input overwhelms the processing capacity and causes a complete shut down or malfunction.

Anyone at any age may experience sensory overload at some point in their lives, particularly in overstimulating environments, or if they are experiencing chronic stress, anxiety, depression, or burnout. Individuals will experience sensory overload differently to each other, some individuals may be highly sensitive to certain stimuli, while others may have a higher or lower threshold for sensory input. Some people may experience it now and again, whilst others can experience it regularly, for these individuals, everyday situations can be challenging.

Sensory overload can affect both children and adults, and is especially common in people with:

• Sensory processing disorder (SPD) – this is a condition in which the brain has trouble receiving and responding to information that comes in through the senses, it can make people more prone to sensory overload
• Attention-Deficit Hyperactivity Disorder (ADHD) – this is a neurodevelopmental condition characterised by persistent symptoms of inattention, hyperactivity, and impulsivity
• Autism Spectrum Disorder (ASD) – this is a neurological and developmental disorder that affects how people interact with others, communicate, learn, and behave.
• Post-Traumatic Stress Disorder (PTSD) – this is a mental health condition that can develop after someone experiences or witnesses a traumatic event.
• Bipolar disorder – this is a mental health condition characterised by mania or hypomania. The DSM-5 notes that some people with the condition experience a sharper sense of smell, hearing, or vision
• Generalised anxiety and anxiety disorder – this is a common mental health condition where individuals often feel very anxious about lots of different things, heightening sensitivity.
• Fibromyalgia – this is a long-term condition that involves widespread body pain and extreme sensitivities
• Brain injuries – these usually result from a violent blow or jolt to the head or body.
• Concussions – these are head injuries that happens when the brain moves or twists inside the skull. Concussions are a type of traumatic brain injury.

Interestingly, a new study has reported that nearly three in four parents report experiencing sensory overload particularly when stressed.

Sensory overload is not an officially recognised condition in the Diagnostic and Statistical Manual of Mental Disorders (DSM 5th edition), due to a lack of research-based evidence to support its own diagnosis, and so is only officially recognised as a possible symptom of other conditions such as those described above. However, other studies have found that although sensory overload can occur together with other disorders, it quite often occurs alone, in the absence of other disorders.

What triggers sensory overload?

Certain sounds, sights, smells, textures, tastes and even movements can bring on sensory overload, and as anyone can experience sensory overload, the triggers will be different for different people. Some of the most common triggers that can cause feelings of being overwhelmed and uncomfortable can include, but are not limited to:

• High-pitched, loud or repetitive noises such as sirens, alarms, construction or gardening tools / machines, children’s screams, thunder, traffic, music, barking dogs, tapping or drumming, background noise(s) etc.
• Strong or overpowering smells and odours such as perfume / aftershave, floral smells, cooking smells, food odours, chemical smells, cleaning products, petrol etc.
• Visual triggers such as bright or flickering lights, bright sunlight, glare or reflections, arrays of colour, patterns, or certain colours, cluttered or crowded environments, fast movement of people and / or objects etc.
• Taste triggers such as strong flavours, spicy foods, hot and cold foods and drinks, food textures, unfamiliar tastes etc.
• Touch triggers such as certain textures, itchy or scratchy materials, tags or labels on clothing, unpredictable or unwelcome physical interactions, invasion of personal space or proximity from others in tightly packed spaces, light or gentle touch, wind or breezes, extreme temperatures, rapid changes in temperature etc.
• Movement triggers can include feeling hesitation going up or down staircases, travellators, escalators, or lifts. Getting or feeling motion or travel sickness in cars, trains or planes. Feeling nervous of activities where the feet leave the ground or when going backwards
• Receiving too much sensory information in a short period whether verbally or visually
• Unpredictable environments, or sudden changes to environmental conditions
• Overstimulating social interactions or group settings
• Rapid changes in motion or direction, or spinning or rotating movements

The main triggers for sensory overload identified by the Chicago study of parents experiencing sensory overload include some more specific trigger examples:

• Children arguing or not getting along with each other (42 percent)
• Loud noise level from children playing, yelling, or crying (37 percent)
• Messiness from toys and clutter (36 percent)
• Noise from television, toys, or music (30 percent)
• Children talking at the same time (29 percent)
• Feeling “touched out” from children wanting to be held or climbing on the parent (16 percent)

People have different sensory sensitivities so what could be a major trigger for one person may only be a mild irritation for another. It is important for anyone who experiences sensory overload to be aware of their own unique triggers in order to manage or avoid them so as to minimise their experiences and the challenges imposed by sensory overload.

What are the signs of sensory overload?

When the brain struggles to process and respond to the sensory information it is receiving, the person may experience particular signs or symptoms, these may be different for each individual, but can include:

• Inability to ignore loud sounds, strong smells, or other types of sensory input
• Extreme sensitivity to clothing or other textures
• Shielding eyes from bright lights
• Covering ears to block out noise
• Avoiding specific environments
• Headaches or migraines 
• Increased heart rate or palpitations 
• Nausea or dizziness 
• Fatigue or muscle tension 
• Heightened anxiety or panic 
• Sweating
• Frustration or irritability
• Loss of focus
• Out of body experience
• Overwhelming feelings of helplessness
• Feeling overwhelmed or agitated
• Insomnia
• Shutting down emotionally or physically

Many adults who experience sensory overload describe the feeling as being assaulted, attacked, or invaded by everyday sensory experiences. In children, sensory overload can present as meltdowns or tantrums and may be mistaken for misbehaviour.

Sensory overload and neurodevelopmental conditions

Neurodevelopmental conditions are disorders that affect the development and functioning of the brain, this may be a result of genetic or environmental factors or a combination of both. These conditions commonly appear in childhood, can range from mild to severe, and they are life-long. Neurodevelopmental conditions such as autism spectrum disorder (ASD) and ADHD can affect how the brain processes sensory information, leading to increased sensitivity and difficulty regulating responses.

ADHD is a common neurodevelopmental condition in which the individual has trouble paying attention to their surroundings, controlling their impulses, or managing their energy levels. Sensory overload or overstimulation significantly impacts individuals with ADHD by disrupting their ability to filter and prioritise sensory information. People with ADHD may find it more difficult to stay still when experiencing sensory overload and this can lead to anxiety, irritability, and difficulty focusing, and may even cause them to avoid overstimulating environments. In a person with ADHD, a noisy, crowded restaurant for example, may trigger anxiety or frustration due to the combination of background chatter and other noise, bright lights, and competing smells.

Children with ADHD can have more difficulty than adults with the condition in regulating their emotional responses and processing input and stimuli from their senses. Physical symptoms of ADHD sensory overload can be different for everyone but may include:

• Inability to sit still, restlessness, and/or fidgeting
• Feeling that clothing is suddenly too tight, itchy, or just uncomfortable
• Exhaustion, sudden tiredness or fatigue
• Migraines or headaches
• Dizziness
• Sleep issues, including difficulty falling or staying asleep

For people with ADHD, everyday life can be challenging needing to balance the need for enough stimulation to keep their brain engaged, without increasing sensory input so much that it leads to sensory overload.

Autism spectrum disorder (ASD) is a lifelong neurodevelopmental condition that affects how individuals communicate, interact, and experience the world. People with ASD can experience both hypersensitivity (over-responsiveness) and hyposensitivity (under-responsiveness) to a wide range of sensory stimuli. Most people have a combination of both. Sensory overload is common in people with ASD and overstimulation in ASD can result in a meltdown or shutdown, or the person using restrictive behaviours such as only eating certain foods, wearing certain fabrics, or avoid particular people or places.

Sensory overload can also cause increased stimming behaviours in people with ASD, these are body movements or sounds that an individual uses to self-soothe, and to regulate their sensory input. Examples of stimming behaviours include rocking backwards and forwards, repeating words or phrases or finger-tapping. Stimming can sometimes seem inappropriate or disruptive in certain settings such as in the workplace, so people with ASD often feel that they need to suppress their stimming. When this happens, it becomes more and more difficult to self-regulate sensory input and overload, and can lead to exhaustion or burnout.

Recent research indicates that sensory overload is a prevalent issue, particularly among autistic individuals and those with other neurodevelopmental conditions. Studies suggest prevalence for sensory overload in between 69% to 93% for people with Autism Spectrum Disorder (ASD), and that almost 50% of children with ADHD exhibit atypical sensory processing.

Sensory overload in children

Sensory overload can happen to all children, although it is more prevalent in children with neurodevelopmental conditions such as ASD and ADHD. It is often first recognised during a child’s toddler years when parents begin to notice that a child has an unusual aversion to certain sensory stimuli such as noise, bright lights, or uncomfortable clothing, and it can cause children to react in unusual ways such as:

• Screaming when their face gets wet
• Throwing tantrums when trying to dress them
• Refusing to wear certain clothes such as those with labels or socks with seams
• Racing around crashing into things
• Extreme responses to or fear of sudden, high-pitched, loud, or metallic noises
• Noticing or being distracted by background noises that others don’t seem to hear
• Avoiding hugs and cuddling even with familiar adults
• Avoiding standing in close proximity to others
• Irritability if touched in the wrong spot
• Being argumentative at mealtimes
• Being very picky with food, or gagging at certain food textures
• Frequently covering their ears or eyes
• Running away from things they do not like
• Becoming stiff and sometimes rigid
• Oversensitivity to pain or temperature
• Difficulties falling asleep or staying asleep
• Over reaction to a change in environment
• Engaging in stimming behaviours such as rocking, hand flapping, head banging etc.

Some of these behaviours can be put down a child entering the “terrible twos”. This is a term used to describe a developmental phase in children between 18 months and 3 years, often characterised by tantrums, defiance, and mood swings. This phase is normal and often begins before a child’s second birthday. It is a time when toddlers are becoming more independent and assert their will, leading to frustration and testing of boundaries. However, in children who experience sensory overload, these temper tantrums and behaviours can be so intense, so prolonged, and almost impossible to stop once they have started.

Children experiencing sensory overload may behave differently from one day to the next and their sensory needs may be context specific or be influenced by other factors, such as mood, tiredness or stress levels. Sensory overload impacts the daily lives of children who experience it, especially once they start school.

A study found that 1 in every 6 children has sensory issues that make it hard to learn and function in school. If parents are aware that their child experiences sensory overload, they should inform the school and speak to the child’s teachers to alert them to the issue and any known triggers, so that the teacher(s) can develop strategies for an easier classroom experience for the child. Children with sensory overload issues will often develop their own coping mechanisms and strategies to manage their sensitivities as they mature.

For many children, sensory sensitivities can diminish or resolve as their sensory systems mature, especially in less severe cases. However, this is often not the case for children with either ASD or ADHD as for them experiencing sensory overload may be a life-long issue.

How to cope with sensory overload

Sensory overload is not an official disorder so it is not possible to get a formal diagnosis, nor is there any specific treatment for sensory overload, although medications that may be prescribed for co-occurring conditions such as anxiety, ASD, or PTSD for example, may also help to reduce sensory overload. Cognitive behavioural therapy (CBT) has also been found to help manage anxiety and fear associated with sensory overload. Alternatively, there are however many ways to learn how to deal with and manage sensory overload and any symptoms.

There are a number of coping techniques, tools and accommodations that can help to provide a calming effect and help a person to regulate their feelings, although everyone has different sensory needs that require different sensory techniques, tools or accommodations, some examples of these include:

Stimming, also known as self-stimulatory behaviour, this is engaging in repetitive body movements such as hand-flapping or rocking, or making noises such as humming, these seem to help some people, especially children, to manage their emotions and to cope with overwhelming situations such as sensory overload. We all use stimming from time to time such as fiddling with a pen when anxious, so as long as stimming does not stray into the realms of causing pain such as when a child uses head banging, it is a reasonably harmless activity and coping strategy.

Sensory fidgets, these have become more well-known over the last few years for calming and focus, helping a person to cope better or manage sensory overload and anxiety, they can benefit children and adults. Fidgets come in different forms, catering to tactile, auditory, and visual preferences. Tactile fidgets such as stress balls can be squeezed and squished when a person is anxious.

Weighted blankets, these can help to relieve anxiety and stress, ease transitions, and prevent melt-downs and repetitive behaviour by providing soothing deep pressure, this gentle pressure from a weighted blanket can help filter out excessive sensory input.

It has been shown that dogs can provide a calming presence for people of all ages. When sensory overload occurs, simply sitting with, holding and stroking a family pet can greatly improve the situation and calm down an individual who is struggling. In addition, walking a dog provides essential daily exercise outdoors.

In the workplace or at school, arrange to use quiet work spaces if possible, or wear headphones to minimise noise, or sunglasses to reduce light. Talk to others and ask them to help reduce sensory inputs, such as by turning down bright lights, or opening a window when strong smells are present. Staying near exits can help to provide a quick escape route should sensory inputs become too overwhelming. Occupational therapists both in the workplace and in schools can collaborate with employers, teachers, families, and other professionals to identify strategies, and provide accommodations and support for people who experience sensory overload.

Deep breathing exercises can help with stress, anxiety and panic that often accompanies sensory overload. One of the easier breathing techniques is box breathing, also known as 4-4-4 breathing:

• Take a breath then exhale on the count of 4
• Hold your breath for 4 seconds
• Inhale to the count of 4
• Hold your breath for 4 seconds
• Repeat

A few rounds of this simple technique is an ideal way to help to keep a raised heart rate down, for calming the nervous system, and reducing stress by concentrating on the breathing and distracting the mind and body.

Muscle relaxation can help to relax muscles that are tense as a result of anxiety. Tensing and relaxing certain muscle groups one at a time leaves the area feeling loose and relaxed, and tension and stress should dissipate. Find a quiet place and sit comfortably, then:

• Focus on breathing, noticing the air coming in and out of the body
• Curl the right foot and squeeze tightly for about 5 seconds. Notice the tension in the foot
• Slowly uncurl the foot and focus on how this feels. The tension will slowly leave the foot
• Repeat the process in various parts of the body, working muscle groups such as in the legs, hands, shoulders and neck. Work up the body, relieving tension along the way, each part of the body will begin to feel lighter, and free from any tension that existed before

Practicing mindfulness, such as meditation or yoga, can help a person to become more aware of their senses and to manage them better. Mindfulness is a practice of paying intense attention to the present moment, without interpretation or judgment. Find a quiet place, this can be indoors or outside:

• Start by standing still, and connecting with your breath and the sensation of your feet on the ground
• Begin to walk slowly and focus on the movement of the body, paying attention to the lifting and falling of the feet, the movement of the legs, and the rhythm of the steps, being aware of the sensations of standing and the subtle movements
• Notice the surroundings, noticing sounds, smells, and sights, gently redirecting attention back to the physical sensations of walking
• There is no need to rush or force it; simply focus on the present moment

This can also provide a gentle form of exercise that can improve circulation and promote a sense of well-being as well as a sense of calm to reduce anxiety.

Reducing technology usage can help to reduce the constant stream of sensory information. Replacing it with calming sounds such as white noise, rain sounds, or calming music, can help to regulate sensory overload, aiding in focus and relaxation especially at bedtime.

Eating a balanced diet, drinking plenty of water and getting proper sleep all contribute to health and wellbeing, helping to reduce stress and anxiety. Reducing sugar intake in the diet can help to improve mood and behaviours. 

Can sensory overload be prevented?

Whilst there is no medical cure for sensory overload, it can often be prevented or reduced by proactively minimising overwhelming stimuli. Paying attention to how the environment contributes to sensory overload, and identifying and being aware of their own particular triggers for sensory overload can help a person to either avoid them, or to put in place strategies for coping and managing them. For example, avoiding music concerts with loud music and flashing lights, turning down bright lights or using dimmer switches, or identifying safe spaces where you are familiar with the sensory stimuli.

Developing routines can be a big help. Knowing when and where sensory overload might occur can help to avoid triggering situations and planning activities and events when sensory stimuli may be lower, such as picking quiet times to shop, or sticking to familiar places where sensory stimuli are a known factor

Employing preventative measures in the home such as choosing neutral or soft colours and textures and avoiding busy patterns in furnishings, de-cluttering, using soft lighting, and minimising background noise can help to create a safe space to help prevent sensory overload.

For children who experience sensory overload, parents/carers should speak to the school and teachers about creating a sensory-friendly classroom environment. Classrooms are filled with sensory stimuli, but by making a few subtle changes to the classroom such as providing a quiet work space to use when needed, giving advance warning and verbal reminders of loud noises such as bells, announcements, or planned fire alarms, and minimising clutter, especially wall clutter, schools can help to minimise triggers for sensory overload.

By learning what symptoms and triggers that you, a loved one, or an employee or pupil may have, you can try various ways to prevent and manage sensory overload.