Autism is a neurodevelopmental difference that affects how a person communicates, interacts socially, and experiences the world sensorially. It is not an illness and there is no single "look" of autism: presentation varies enormously between children, and between boys and girls, which is part of why some children, particularly girls, are identified later than others.
Differences some parents and carers notice
No single sign confirms autism, and every child develops at their own pace, but differences that sometimes lead a parent to seek an assessment include limited or inconsistent eye contact, delayed speech and language development or unusual patterns of speech, a strong preference for routine and distress when routines change, intense, narrow interests, repetitive movements or behaviours, and sensory sensitivities to sound, light, texture or touch.
What to do if you notice these patterns
None of the differences above are, on their own, a diagnosis. If you notice a pattern of these traits over time and it is affecting your child's wellbeing, school life or family life, the appropriate next step is a structured developmental assessment with a licensed clinician, such as a paediatrician, clinical psychologist or psychiatrist experienced in neurodevelopmental assessment. Early identification does not change who your child is, but it can open the door to the right support at school and at home.