What are the signs and symptoms of autism?

Signs of autism usually appear during early childhood, by age 2 or 3. Some development delays can appear earlier, as early as 18 months. Symptoms may also appear later. Not all children with autism show all the signs, and many children who don’t have autism show a few.

Some of the more common signs that may indicate a person has autism include:

Speaking later than typical or not at all (nonverbal)
Persistent repetition of words or phrases (echolalia), hand flapping, or any repeated movement
Atypical nonverbal communication, including avoiding eye contact, giving few facial expressions, or having a monotone
A preference for solitary play
Becoming extremely distressed by changes in routine or surroundings, including new foods or changes in schedule
Highly focused interests or hobbies
Unusual and sometimes intense sensory reactions to sounds, smells, tastes, textures, lights and/or colours

Some autistic people might experience additional symptoms, including:

Delayed movement, language, or cognitive skills
Seizures
Gastrointestinal symptoms, like constipation or diarrhoea
Excessive worry or stress
Hyperactive, inattentive or impulsive behaviours
Unexpected emotional reactions or meltdowns
Unusual eating habits or preferences
Unusual sleep patterns

Interesting fact

Around 10 per cent of autistic people have skills such as maths or drawing that are of extraordinary ability.