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A boy looking down at colored wooden blocks.

What are the symptoms of autism?

The symptoms of one person with autism can be very different from the symptoms of another person with autism. Health care providers think of autism as a spectrum disorder—which means that there is a range of similar features in different people with the disorder.1

One person with autism may have mild symptoms, while another may have more serious symptoms, but they both have autism spectrum disorder (ASD).

Despite the range of possible symptoms, there are certain actions and behaviors that are common in ASD and could signal that a child is on the autism spectrum. Parents and caregivers who notice these "red flags" should speak to their child's health care provider about autism and screening the child for ASD.

In general, the main signs and symptoms of ASD relate to:

  • Communication and interactions with other people
  • Routines or repetitive behaviors, sometimes called stereotyped (pronounced STER-ee-uh-tahypt) behaviors

Health care providers organize some noticeable symptoms of autism into "red flags" to help parents and caregivers know what to look for as children grow and develop. These red flags are listed below.

​​Red Flags for ASD2,3

  • Communication

  • Social Behavior

  • Stereotyped Behavior

  • Other Behavior

You can find age-specific milestones on the Centers for Disease Control and Prevention website Learn the Signs. Act Early. If your child does not meet developmental milestones, talk to his or her health care provider about screening for ASD.

Note about these red flags:

  • Some of these red flags apply only at certain ages, so consider what is typical for other children your child's age.
  • Some red flags are more strongly associated with autism than others.
  • If your child shows any red flags for autism, talk to his or her health care provider.

Citations

​ ​
  1. Diagnostic and Statistical Manual of Mental Disorders, 5th Edition. (2013). American Psychiatric Association: Washington, DC. [top]
  2. Johnson CP, & Myers SM; American Academy of Pediatrics Council on Children with Disabilities. (2007). Identification and evaluation of children with autism spectrum disorders. Pediatrics, 120(5), 1183-1215. [top]
  3. CDC. Autism Spectrum Disorders—Signs & Symptoms. (2015). Retrieved January 10, 2017, from http://www.cdc.gov/ncbddd/autism/signs.html. [top]

What are the symptoms of autism?

When do children usually show symptoms of autism?

What causes autism?

How many people are affected by autism?

How do health care providers diagnose autism?

What are the treatments for autism?​​​​

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