About autism
Find out what autism is and explore the ‘core characteristics’ of autism needed for a diagnosis.

What is autism?
A definition of autism with an overview of communication, behaviours and interests, and sensory processing differences needed for an autism diagnosis.
Read moreDo vaccines or paracetamol cause autism?
No, there is no evidence that vaccines or paracetamol cause autism. For more information, visit our page The causes of autism.
The core characteristics of autism
Communication
Behaviours and interests
A lot of medical and professional literature refers to these differences as ‘restricted and repetitive behaviours and interests’ (RRBIs). Autistic people may describe them as ‘stimming’ (stimulatory) or ‘self-regulatory’ behaviours – ways to keep calm and happy.
Sensory processing
Sensory processing differences are not a standalone core characteristic. During diagnosis, these are considered part of ‘RRBIs’ (behaviours and interests). This is because of the reactions they may cause.
Practical resources
Autistic sensory experiences
Understand a wide range of sensory processing differences, covering:
- hyper-sensitivity and hypo-sensitivity
- common sensory triggers
- reactions and challenges faced
- self-management and support.
My sensory experience
You can type into or print off this ‘do-it-yourself' resource. It can help you think about:
- your experience of sensory inputs
- your triggers of hyper-sensitivity (if you experience this)
- your reactions to sensory inputs and challenges you face
- how you can manage sensory input and how other people can support you.