What is sensory processing, and what does seeking or avoiding look like?
Sensory processing is how the nervous system receives, organises and responds to sensory information. Everyone has a profile; some children's is far enough from the average that everyday environments are genuinely difficult, and the resulting behaviour is routinely misread as naughtiness or fussiness.
The senses involved include two people forget:
Proprioception, the sense of where your body is, from muscles and joints.
Vestibular, balance and movement, from the inner ear.
Alongside touch, sound, sight, taste, smell and interoception — internal signals like hunger, temperature and needing the toilet.
Over-responsiveness (avoiding) can look like: distress at labels, seams and certain fabrics; refusing hair washing, brushing and nail cutting; covering ears at hand dryers or assemblies; extreme food selectivity driven by texture and smell rather than preference; dislike of being touched unexpectedly; and meltdowns after busy environments like supermarkets and parties — frequently after rather than during, once the child is somewhere safe.
Under-responsiveness and seeking can look like: constant movement, crashing, jumping and spinning; chewing clothing; seeking deep pressure and tight spaces; loud voice; touching everything; high pain tolerance; and appearing not to hear.
Children are frequently both, seeking in one sense and avoiding in another, which is why a single label rarely fits.
What helps:
Change the environment first — reduce noise, allow ear defenders, remove labels, give warning before transitions, provide a quiet exit.
Build in movement before demanding stillness, since proprioceptive input is regulating for most children.
Respect the response as real. "It's not that loud" is not useful information to a nervous system reporting otherwise.
Prepare, since predictability reduces load considerably.
Where to get help. An occupational therapist is the relevant professional, via a GP, health visitor or school.
A note on evidence. Sensory differences are well documented and are a recognised feature of autism and ADHD. "Sensory processing disorder" as a standalone diagnosis is not universally accepted, and some specific sensory-integration therapies have weak evidence — environmental adjustment is better supported than intensive treatment.