Sensory Processing in Autism and ADHD: Why Everyday Experiences Can Feel So Different

Have you ever wondered why one person can happily sit in a noisy café while another feels completely overwhelmed within minutes? Or why a child refuses to wear certain clothes, covers their ears at the sound of a hand dryer, constantly chews on their sleeves or seems to seek out movement all day long?

These experiences are often linked to sensory processing differences, which are common in both autistic people and individuals with ADHD.

Sensory processing is not simply about being "sensitive". It is about how the brain receives, interprets and responds to information coming from the senses. For some people, everyday sensory experiences can feel much more intense, barely noticeable, or difficult to filter, making daily life far more exhausting than it may appear to others.

What is sensory processing?

Every second of the day, our brains receive information from our senses. Most people think of the five senses:

• Sight

• Hearing

• Touch

• Taste

• Smell

However, there are actually several additional sensory systems that play an equally important role:

• Vestibular – helps us understand movement and balance.

• Proprioception – tells us where our body is in space and how much force we are using.

• Interoception – helps us recognise internal body signals such as hunger, thirst, pain, temperature, tiredness or the need to use the toilet.

For many autistic people and individuals with ADHD, these sensory systems work differently. The brain may struggle to regulate or filter sensory information, leading to experiences that can be overwhelming, distracting or difficult to interpret.

Sensory processing in autism

Sensory differences are recognised within the diagnostic criteria for autism (DSM-5-TR) and are considered a core characteristic of many autistic people.

Autistic individuals may experience:

• Increased sensitivity (hypersensitivity)

• Reduced sensitivity (hyposensitivity)

• A mixture of both, depending on the sense or situation

These differences can affect every aspect of daily life.

For example, an autistic child may:

• Cover their ears during assemblies or when a vacuum cleaner is used.

• Refuse certain clothing because labels or seams feel painful.

• Eat only a limited range of foods due to texture rather than taste.

• Become distressed in busy supermarkets or shopping centres.

• Avoid hugs or unexpected touch.

• Seek repetitive movement such as rocking, spinning or swinging because it helps regulate their nervous system.

Many autistic adults describe constantly scanning their environment for sensory information. Bright lights, background conversations, perfume, traffic noise and uncomfortable clothing can all compete for attention simultaneously, making everyday environments incredibly tiring.

Sensory processing in ADHD

Although sensory processing is not part of the diagnostic criteria for ADHD, research consistently shows that sensory differences are extremely common.

People with ADHD may experience difficulties because their brains find it harder to filter out unimportant sensory information.

This can mean they notice everything at once.

For example:

• Every conversation happening in a classroom.

• The ticking of a clock.

• Someone tapping a pencil.

• A flickering light.

• Clothing rubbing against their skin.

Rather than helping them focus, these competing sensory inputs can make concentration much more difficult.

Many people with ADHD also actively seek sensory input to help regulate attention and alertness.

This might include:

• Fidgeting.

• Constant movement.

• Tapping feet.

• Chewing pens or clothing.

• Listening to music whilst working.

• Playing with tactile objects.

• Pacing whilst thinking.

These behaviours are often misunderstood as distraction or "bad habits", when in reality they may help the brain maintain focus.

Can someone be both sensory seeking and sensory sensitive?

Yes. This often surprises people.

Someone may actively seek one type of sensory input while avoiding another.

For example, a child might:

• Love swinging and trampolining.

• Constantly crash into cushions.

• Enjoy tight hugs.

Yet at the same time:

• Refuse certain clothing.

• Become distressed by loud noises.

• Avoid busy places.

• Gag at certain food textures.

Sensory profiles are highly individual and can change depending on stress, fatigue, illness or anxiety.

What does sensory overload feel like?

Sensory overload occurs when the brain receives more sensory information than it can comfortably process.

Everyone experiences this occasionally, but autistic people and individuals with ADHD may reach this point much more quickly.

Sensory overload can lead to:

• Feeling overwhelmed.

• Difficulty concentrating.

• Increased anxiety.

• Irritability.

• Emotional outbursts.

• Meltdowns.

• Shutdowns.

• Needing to escape the environment.

• Feeling physically exhausted afterwards.

Importantly, this is not an overreaction or a behavioural choice.

It is the nervous system becoming overloaded.

What about sensory under-responsiveness?

Not everyone experiences sensory input as "too much."

Some people need more sensory input than others before they notice it.

They may:

• Not notice pain easily.

• Have a high tolerance for temperature.

• Constantly seek movement.

• Enjoy deep pressure.

• Need louder music.

• Miss hunger or thirst cues.

• Forget to use the toilet until the last minute.

This can sometimes be misunderstood as carelessness or lack of awareness when it actually reflects differences in sensory processing.

Why does anxiety make sensory differences worse?

Sensory processing and anxiety often influence one another.

When we are anxious, our nervous system becomes more alert, making sounds seem louder, lights brighter and touch more uncomfortable.

Likewise, ongoing sensory overload can increase stress and anxiety.

Many autistic people and individuals with ADHD describe living in a constant state of heightened alertness because their brains are continually processing more sensory information than those around them.

Understanding this relationship can help explain why some days feel much harder than others.

Supporting sensory needs

There is no single approach that works for everyone.

The goal is not to remove every sensory challenge, but to better understand individual sensory needs and make reasonable adjustments where possible.

Helpful strategies may include:

• Providing quiet spaces to regulate.

• Allowing movement breaks throughout the day.

• Using ear defenders or noise-cancelling headphones when appropriate.

• Offering fidget tools or sensory objects.

• Choosing comfortable clothing without irritating seams or labels.

• Respecting food preferences linked to texture.

• Preparing for busy environments in advance.

• Using visual schedules to reduce uncertainty alongside sensory demands.

Identifying early signs of sensory overload before distress escalates.

Sensory processing and masking

Many autistic people, particularly girls and women, learn to hide or suppress their sensory differences.

They may tolerate overwhelming environments throughout the day, only to become exhausted, irritable or emotionally overwhelmed once they return home.

Others may quietly endure discomfort because they worry about appearing "different."

This masking can make sensory difficulties less visible but no less significant.

Final thoughts

Sensory processing differences are a fundamental part of many autistic and ADHD experiences.

Understanding these differences helps us move away from viewing behaviours as "challenging" or "attention-seeking" and instead recognise them as meaningful responses to how an individual's nervous system experiences the world.

Whether someone seeks movement, avoids certain sounds, wears the same comfortable clothing every day or needs regular quiet time, these are often adaptive strategies that help them regulate and participate in everyday life.

When we understand sensory processing, we are better able to create environments where autistic people and individuals with ADHD can feel comfortable, understood and supported,

not by changing who they are, but by recognising and respecting the way their brains experience the world.

If you’re looking for clear, compassionate support in understanding sensory differences alongside autism or ADHD, CADS (Clinical Autism & ADHD Diagnostic Services) offers neuro-affirming, multidisciplinary assessments for children, young people and adults across Leicestershire, Northamptonshire, Rutland and the wider UK. We take time to understand the whole person, provide detailed feedback, and share practical recommendations tailored to everyday life.

To discuss your concerns and find out whether an assessment feels right for you or your family, please get in touch via tania@cadsautism.co.uk, or visit https://www.cadsautism.co.uk/.