Autism spectrum disorders (ASD) can be hard to diagnosis. 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. They may also see a backslide or stop in development. 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 one or more of the following:

• 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 your 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.

The doctor will gather information to make the diagnosis. Specialists may also be involved to confirm the diagnosis