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Diagnosis of Autism Spectrum Disorders

  • Amy Scholten, MPH
Publication Type:

Condition InDepth

Diagnosis of Autism Spectrum Disorders

Autism spectrum disorders (ASD) can be hard to diagnose. There is no one test to confirm it. Symptoms can also vary between children. Other health problems may also cause symptoms similar to ASD. Parents may be the first to notice certain behaviors or changes. A doctor may also notice issues during a routine visit.

Not all development changes are due to ASD. Tests may be done to collect more information. Other possible causes will need to be ruled out. Tests may include:

  • A physical exam. It will include looking for responses common to ASD. The doctor may ask about:
    • Problems interacting with others
    • Not sharing
    • Problems understanding or keeping relationships
    • Not using speech when it should be used
    • Repetitive use of objects, movements, or speech
    • Inflexibility to change
    • Intense focus
    • Overreaction to sensory information
  • Psychological tests—A interview will test how the child answers certain questions. The answers will be compared to others of the same age. Other tests will measure motor skills, and hand or eye coordination. Their abilities will be compared to children the same age.
  • Genetic tests—There is no specific gene for ASD. However, certain genetic conditions, such as fragile X syndrome, also have an increased risk of ASD.
  • Imaging tests—To look for brain injury.
  • EEG—To check the electrical activity of the brain. Seizure disorders will also be rules out.

The doctor will gather information. Specialists usually confirm the diagnosis


  • Autism spectrum disorder. National Institute of Mental Health website. Available at: https://www.nimh.nih.gov/health/topics/autism-spectrum-disorders-asd.
  • Autism spectrum disorders. EBSCO DynaMed website. Available at: https://www.dynamed.com/condition/autism-spectrum-disorders.
  • How is autism diagnosed? Healthy Children—American Academy of Pediatrics website. Available at: https://www.healthychildren.org/English/health-issues/conditions/Autism/Pages/Diagnosing-Autism.aspx.
  • Screening and diagnosis of autism spectrum disorders. Centers for Disease Control and Prevention website. Available at: https://www.cdc.gov/ncbddd/autism/screening.html.
  • What are early signs of autism? HealthyChildren.org—American Academy of Pediatrics website. Available at: https://www.healthychildren.org/English/health-issues/conditions/Autism/Pages/Early-Signs-of-Autism-Spectrum-Disorders.aspx.


  • Adrian Preda, MD
Last Updated:

This content is reviewed regularly and is updated when new and relevant evidence is made available. This information is neither intended nor implied to be a substitute for professional medical advice. Always seek the advice of your physician or other qualified health provider prior to starting any new treatment or with questions regarding a medical condition.