Diseases & Conditions A - Z
powered by Talix

Autism Diagnosis

Diagnosing Autism

Autism spectrum disorder (ASD) is a group of brain-based disorders that affect a child's behavior, communication, and social skills. ​Because most children with an ASD will master early motor skills such as sitting, crawling, and walking on time, parents may not initially notice delays in social and communication skills.

ASDs are developmental disorders whose symptoms may change with maturation and intervention. While rare, some children improve so much that they no longer can be considered to have an ASD. Most of these children may have other developmental, learning, language, or behavioral diagnoses.

The sooner an ASD is identified, the sooner an intervention program can start. Each child with autism has different needs. The intervention that helps one child may not be as helpful for another. Starting an intervention program as soon as possible can improve outcomes for many children with an ASD, so children can and should be referred for diagnosis and early intervention (EI) as soon as the ASD symptoms are noted.

Autism Symptoms

No two children with ASD have exactly the same symptoms. According to the National Institute of Mental Health, there are standard criteria for the diagnosis of ASD. The following are examples of how a child with an ASD may act:

Social Differences

Social differences in children with ASD can vary. Be aware of a child who:

  • doesn't keep eye contact or makes very little eye contact
  • doesn't respond to a parent's smile or other facial expressions
  • doesn't look at objects or events a parent is looking at or pointing to
  • doesn't point to objects or events to get a parent to look at them
  • doesn't bring objects of personal interest to show to a parent
  • doesn't often have appropriate facial expressions
  • is unable to perceive what others might be thinking or feeling by looking at their facial expressions
  • doesn't show concern (empathy) for others
  • is unable to make friends or uninterested in making friends

Communication Differences

Communication issues may indicate ASD. Be aware of a child who:

  • doesn't point at things to indicate needs or share things with others
  • doesn't say single words by 16 months
  • repeats exactly what others say without understanding the meaning (often called parroting or echoing)
  • doesn't respond to name being called but does respond to other sounds (like a car horn or a cat's meow)
  • refers to self as "you" and others as "I," and may mix up pronouns
  • often doesn't seem to want to communicate
  • doesn't start or can't continue a conversation
  • doesn't use toys or other objects to represent people or real life in pretend play
  • may have a good rote memory, especially for numbers, letters, songs, TV jingles, or a specific topic
  • may lose language or other social milestones, usually between the ages of 15 and 24 months (often called regression)

Behavioral Differences (repetitive and obsessive behaviors)

Behavioral differences often include repetitive and obsessive behaviors. Pay attention if your child:

  • rocks, spins, sways, twirls fingers, walks on toes for a long time, or flaps hands
  • likes routines, order, and rituals and has difficulty with change
  • obsessed with a few or unusual activities, doing them repeatedly during the day
  • plays with parts of toys instead of the whole toy (for example, spinning the wheels of a toy truck)
  • doesn't seem to feel pain
  • is very sensitive or not sensitive at all to smells, sounds, lights, textures, and touch
  • has an unusual use of vision or gaze and looks at objects from unusual angles

Developmental Tests

Your family doctor or pediatrician should perform routine developmental screening tests at all well child checkups. There is no single test that can verify an ASD. Parents are usually the first to notice potential problems in a child’s development. If you believe your child is slow in developing language or social skills, talk with your pediatrician.

The Centers for Disease Control and Prevention (CDC) lists a number of tests to use in the initial screenings for an ASD. These include:

  • Ages and Stages Questionnaires (ASQ)
  • Communication and Symbolic Behavior Scales (CSBS)
  • Parents’ Evaluation of Developmental Status (PEDS)
  • Modified Checklist for Autism in Toddlers (M-CHAT)
  • Screening Tool for Autism in Toddlers and Young Children (STAT)
  • Autism Spectrum Screening Questionnaire (ASSQ)
  • Australian Scale for Asperger's Syndrome
  • Childhood Asperger’s Syndrome Test (CAST) 

Comprehensive Testing

If screening tests spot problems, then your child will need comprehensive testing by specialists. When an ASD is suspected as a cause of language and social delays, the child should be referred for a full evaluation to determine if an ASD is the proper diagnosis. The evaluation may be done by a doctor or psychologist who has expertise in the diagnosis of ASD or, preferably, by a team of specialists who may include:

  • developmental pediatricians
  • child neurologists
  • child psychiatrists
  • psychologists
  • speech or language pathologists
  • occupational or physical therapists
  • educators
  • social workers

Testing of developmental domains may occur through the school system.

Typically, an evaluation will include:

  • careful observation of play and child-caregiver interactions
  • detailed history and physical examination
  • developmental assessment of all skills (motor, language, social, self-help, cognitive). ASD is suspected when the child's social and language functioning are significantly more impaired than the overall level of motor, adaptive, and cognitive skills
  • hearing test. All children with any speech delays or those suspected of having ASD should have their hearing formally tested.
  • language evaluation that provides standardized scores of expressive language and receptive language, as well as an evaluation of pragmatic language and articulation

Diagnosis of an ASD is made by applying specific diagnostic criteria using all the information collected by history, observation, and testing.

Educational Diagnosis

Qualified school officials can also make what is called an educational diagnosis. This type of diagnosis is used to determine your child’s specific needs and what services can be provided for him or her in a school environment. This diagnosis is not necessarily dependent on a medical diagnosis.

Content licensed from:

Written by: the Healthline Editorial Team
Medically reviewed on: Aug 28, 2014: George Krucik, MD, MBA

This feature is for informational purposes only and should not be used to replace the care and information received from your health care provider. Please consult a health care professional with any health concerns you may have.
Symptom Search
Enter your symptoms in our Symptom Checker to find out possible causes of your symptoms. Go.
Drug Interaction Checker
Enter any list of prescription drugs and see how they interact with each other and with other substances. Go.
Pill Identifier
Enter its color and shape information, and this tool helps you identify it. Go.
Drugs A-Z
Find information on drug interactions, side effects, and more. Go.