Need Personalized Support? Our Autism Response Team is here to provide information, tools, and resources. Connect Now

Signs & Symptoms

The core symptoms of autism are social communication challenges and restricted, repetitive behaviors.

Signs of Autism in Children

The autism diagnosis age and intensity of autism’s early signs vary widely. Some infants show hints in their first months. In others, behaviors become obvious as late as age 2 or 3.

Not all children with autism show all the signs. Many children who don’t have autism show a few. That’s why professional evaluation is crucial.

The following may indicate your child is at risk for an autism spectrum disorder. If your child exhibits any of the following, ask your pediatrician or family doctor for an evaluation right away:

By 6 months:

  • Few or no big smiles or other warm, joyful and engaging expressions
  • Limited or no eye contact

By 9 months:

  • Little or no back-and-forth sharing of sounds, smiles or other facial expressions

By 12 months:

  • Little or no babbling
  • Little or no back-and-forth gestures such as pointing, showing, reaching or waving
  • Little or no response to name

By 16 months:

  • Very few or no words

By 24 months:

  • Very few or no meaningful, two-word phrases (not including imitating or repeating)

At any age:

  • Loss of previously acquired speech, babbling or social skills
  • Avoidance of eye contact
  • Persistent preference for solitude
  • Difficulty understanding other people’s feelings
  • Delayed language development
  • Persistent repetition of words or phrases (echolalia)
  • Resistance to minor changes in routine or surroundings
  • Restricted interests
  • Repetitive behaviors (flapping, rocking, spinning, etc.)
  • Unusual and intense reactions to sounds, smells, tastes, textures, lights and/or colours

Symptoms of autism in Children

The core symptoms of autism are social communication challenges and restricted, repetitive behaviors. Specialized healthcare providers diagnose autism using a checklist of criteria in the two categories above. They also assess autism symptom severity. Autism’s severity scale reflects how much support a person needs for daily function.

Many people with autism have sensory issues. These typically involve over- or under-sensitivities to sounds, lights, touch, tastes, smells, pain and other stimuli.

Autism is also associated with high rates of certain physical and mental health conditions

Symptoms of autism may:

  • begin in early childhood (though they may go unrecognized)
  • persist
  • interfere with daily living

Social Communication Challenges

Children and adults with autism have difficulty with verbal and non-verbal communication. For example, they may not understand or appropriately use:

  • Spoken language (around a third of people with autism are nonverbal)
  • Gestures
  • Eye contact
  • Facial expressions
  • Tone of voice
  • Expressions not meant to be taken literally

Additional social challenges can include difficulty with:

  • Recognizing emotions and intentions in others
  • Recognizing one’s own emotions
  • Expressing emotions
  • Seeking emotional comfort from others
  • Feeling overwhelmed in social situations
  • Taking turns in conversation
  • Gauging personal space (appropriate distance between people)

Restricted and Repetitive Behaviors

Additional social challenges can include difficulty with:

  • Repetitive body movements (e.g. rocking, flapping, spinning, running back and forth)
  • Repetitive motions with objects (e.g. spinning wheels, shaking sticks, flipping levers)
  • Staring at lights or spinning objects
  • Ritualistic behaviors (e.g. lining up objects, repeatedly touching objects in a set order)
  • Narrow or extreme interests in specific topics
  • Need for unvarying routine/resistance to change (e.g. same daily schedule, meal menu, clothes, route to school)

Related resources from our online community—Autism Speaks Canada Autism Response Team

Back to: Causes of Autism

Up Next: Screening