Doctors can use blood and urine tests to diagnose some diseases or medical problems. This is not true of an autism diagnosis. Your doctor will need to learn about your child’s behavior at certain ages to decide if your child is autistic. Your doctor will also need to rule out other things that might cause your child to act the way he does.

Doctors make a medical autism diagnosis based on certain tests and a child’s very specific symptoms. A doctor can sometimes make an autism diagnosis when a child is 18 months old or even younger. An autism diagnosis at age 2 is even more reliable. Two steps can help a doctor decide if your child is on the autism spectrum:

  • Developmental Screening, and a
  • Full Diagnostic Evaluation

Developmental Screening

All doctors should “screen” or test children for signs of autism during regular office visits. The screenings are short tests to help a doctor decide if a child is developing at a normal rate. Doctors should give children tests to detect disabilities and delays in development when a child is:

  • 9 months
  • 18 months, and
  • 24 or 30 months old

They should also specifically test for autism at ages:

  • 18 months, and
  • 24 months

The doctor will conduct these tests by asking the parents questions about the child’s learning and behavior. The doctor may also talk and play with the child to see how the child:

  • learns or understands things
  • speaks
  • behaves, and
  • interacts with people

If a doctor notices signs of autism in a child, the doctor should do a full (comprehensive) diagnostic evaluation on the child.

Comprehensive Diagnostic Evaluation

A doctor can more easily diagnose a child’s autism spectrum disorder (ASD) with a full evaluation. This may include:

  • obtaining more detailed information about the child’s development and behavior
  • hearing tests
  • vision tests
  • genetic tests
  • neurological tests, and
  • other medical tests that may help the doctor make a decision

A child’s pediatrician may also refer a child to a specialist for further testing. These specialists may include:

  • doctors who specialize in child development
  • child neurologists, and
  • psychologists or psychiatrists who treat children

An early autism diagnosis can enable you to get the help your child needs. If your doctor has not given your child these tests, ask the doctor to do so or to refer you to someone else.

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