The sensory system includes; touch, taste, smell, sound, sight, proprioception and the vestibular system. Sensory issues are caused by the disorganised way the brain processes information from the senses. If there is a sensory issue, the sensory system is either over-sensitive or under-sensitive. However, this can be different for each sense. For example, someone can be under-sensitive to touch, but over-sensitive to sound.

Over-sensitive means that senses are heightened. For example, a person may hear noises from far away or lights may be seen much brighter.

Under-sensitive means that the senses are under developed and a person receives less stimuli. For example, a person may not notice extreme odours, or have a very high pain threshold.

Someone with autism may find it difficult to have a conversation with others and may unintentionally over talk about their special interest. Despite others trying to change topic, or giving visual cues like checking their watch or looking away, the person will continue to talk.

Sight

Fluorescent lights can seem overly bright to someone who is over-sensitive.

Lights in bedroom or on street can make it more difficult to sleep.

Under-sensitivity can cause poor depth perception resulting in clumsiness.

Over-sensitive: Don’t use fluorescent lights, use blackout blinds or curtains in bedrooms, wear sunglasses.

Under-sensitive: Make a high walled desk in school work or home for studying or working to reduce visual distractions.

Loud and sudden noises can become very distressing to a person who is over-sensitive.

Over-sensitivity can make it difficult to filter out background noise.
If someone is under-sensitive to sound they may only hear in one ear. they may also enjoy loud noises and loud environments.

Over-sensitive: use earplugs or noise cancelling headphones, practice fire drills and smoke alarms, closing doors and windows to limit outdoor noise.

Under-sensitive: use visual supports to support verbal information.

Over-sensitivity: To touch can result in not enjoying hugs, shaking hands or being in close proximity to people. For instance on public transport.

The feel of certain fabrics against skin can cause huge levels of discomfort for some over-sensitive people.

Under-sensitive: People enjoy weighted blankets and can have a high pain threshold.

Over-sensitive: Removing tags from clothing, investing in sensory supports for brushing hair and teeth, slowly introduce new textures in objects and foods.

Under-sensitive: Use weighted blankets to provide stimulation.

The texture of certain foods may cause discomfort to someone who is over-sensitive. For instance, only smooth foods like mashed potato or yogurt is eaten.

A person who is under-sensitive may prefer very spicy foods or may eat non edible objects. This is called Pica.