Guide to the Signs & Symptoms of Autism

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Autism, or autism spectrum disorder (ASD), impacts as many as 1 in every 54 children in the U.S., the Centers for Disease Control and Prevention (CDC) reports. Main indicators of autism are issues with social communication and interactions in conjunction with repetitive and specific behaviors.

As a spectrum disorder, ASD causes a range of impairment issues. While some people can perform many daily tasks and live independently, others may have a higher level of disability that interferes with daily functioning.

Signs of ASD can be recognized early on, even in babies, though they become more prevalent as a child enters toddlerhood. The National Institutes of Health (NIH) recommends that toddlers should be screened for autism specifically between 18 and 24 months. Children with ASD can also develop normally up until age 2 or 3 before symptoms start to appear.

While symptoms of autism can vary with age and severity, earlier diagnoses and treatments always result in better outcomes.

Autism can be successfully managed through therapies and early intervention methods. Targeted therapies can improve daily life functioning, communication, and social skills, bringing an enhanced quality of life to autistic individuals.

Spotting Autism

ASD is a spectrum disorder, which means that there are ranges of severity and therefore some variety in the symptoms. It is a complex neurological disorder that typically manifests in early childhood. Autism can significantly impair social interactions, communication, and completion of daily life tasks.

The American Psychiatric Association’s (APA) Diagnostic and Statistical Manual of Mental Disorders (DSM-5), published by the American Academy of Pediatrics (AAP), reports that autism symptoms include:

  • Difficulties with social interaction, including initiating and maintaining conversations.
  • Issues sharing emotions, empathizing with others’ emotions, and shared attention.
  • Problems with nonverbal communication skills, such as making eye contact, tone and body language, and understanding these cues from others.
  • Trouble maintaining social relationships, understanding or relating to others, adjusting to social expectations, and participating in age-appropriate activities.

According to the standard diagnostic criteria, an individual must also show two of four additional symptoms in order to be diagnosed with ASD. These symptoms are:

  • Resistance to change, ritualistic patterns, and strict adherence to change.
  • Repetitive speech patterns, object usage, or movements.
  • Unusual attention to sensory input or aspects of the surrounding environment.
  • Intense focus on precise chosen interests.

There are specific signs of autism that vary based on developmental age, which can be used to spot the disorder as well.

Early Warning Signs of Autism

ASD signs are typically noticeable by age 2 or 3, but symptoms are often present earlier. While autism can be diagnosed as young as 18 months, it is more reliably diagnosed when a child is 2 years old.

The process from recognizing a potential issue to an autism diagnosis can be long and complicated. The earlier signs are identified, the sooner treatment can begin.

Early intervention is the key to cultivating overall functioning and developing coping skills for managing ASD. This early treatment improves long-term outlooks significantly. 

Some early signs of ASD include:

  • Little or no talking.
  • Speaking later than is developmentally expected.
  • Abnormal nonverbal communication skills, such as avoidance of eye contact, lack of facial expressions, or a monotone speaking style.
  • Not engaging in cooperative play with peers but instead focusing on parallel or solitary play.
  • Repetitive movements, words, or sounds.
  • Difficulties with change, especially altered schedules.
  • Extreme focus on a specific toy or interest.
  • Preference for structured play that is predictable as opposed to spontaneous.

Autism often co-occurs with other disorders as well. The presence of other disorders, such as gastrointestinal and sleep disorders, can raise the likelihood of autism. Parents of children with these disorders should be on heightened alert for the signs of ASD.

The CDC publishes a list of typical developmental milestones to help parents be aware that their children are on track. Knowledge of these milestones can help parents identify possible delays and disorders, such as ASD, more easily.

Recognizing Autism in Different Age Groups

ASD knows no socioeconomic, racial, or cultural boundaries. It impacts people from all demographics and backgrounds, though certain populations are at higher risk for the disorder. Autism spectrum disorder is over four times more common in boys than girls.

Today, more children have been diagnosed with autism than ever before. It is believed that better diagnostic tools and an improved understanding of autism are behind the higher number of diagnoses in the past two decades.

As a spectrum disorder, ASD signs and symptoms can vary based on age and the severity of the disorder. Below are some common things to look for based on age.


  • No babbling with parents
  • Lack of response to name
  • No pointing at objects or people
  • Lack of social responses and smiling
  • Intense focus on singular objects


  • No words by 16 months or no phrases of at least two words by age 2
  • Loss of social skills or language that was already acquired
  • Lining up toys or objects excessively
  • Minimal social interaction 
  • Poor eye contact
  • Obsessive interest in things, such as how wheels roll on a toy car
  • Regression of previously learned language skills or motor functions


  • Prefers solitary play or parallel play over collaborative play with peers
  • Difficulty making friends
  • Preoccupation with specific topics or objects
  • Inflexibility surrounding routines and resistance to change
  • Trouble initiating and sustaining conversations
  • Issues with self-regulation
  • Difficulties understanding body language, nonverbal cues, and emotion in others
  • Problems with shared experiences and social interactions
  • Prefers rigid and structured play as opposed to “make-believe” or imaginative play
  • Repetitive movements and language patterns, such as echolalia
  • Emotional outbursts, especially when overstimulated
  • Monotone, sing-song, or “robot” voice
  • Awkward or inappropriate use of language
  • Increased sensitivity to sensory input


  • Social isolation
  • Difficulties understanding and relating to emotions in others
  • Lack of interest in other people
  • Intense and specific focus on singular topics or subjects
  • Trouble with emotional regulation
  • Inability to read and interpret social cues and body language
  • Difficulty keeping up with a conversation
  • Extreme attention to detail, which can include excelling in science, math, art, or music
  • Sleep issues
  • Irritability

Early Intervention Is Key

ASD is both a spectrum disorder with ranges in severity and disability as well as a developmental disorder.

While autism is typically noticeable by toddler age, some children can develop coping skills that mask ASD until later in life. In these cases, autism can often go unnoticed until social demands extend beyond the ability to cope with them. This often coincides with entering school.

Early intervention and treatment for ASD can offer children the best chance at fulfilling lives. As a result, it is vital to be on the lookout for autism symptoms early on in life and to start the diagnostic process as soon as possible. ASD can be suspected in infanthood and officially diagnosed in a young toddler.

Behavioral signs of autism are often evident between 6 and 12 months, but many developmental delays can even out by around 24 months. For example, some children are simply late walkers or talkers, and this doesn’t signify autism. This is why the autism spectrum disorder diagnosis is not typically considered to be “stable” and definitive until at least 18 months.

Children who are considered “high functioning” on the ASD spectrum may begin school before problems start to really appear. It is often in this school environment that the self-developed coping skills are challenged socially.

By keeping a vigilant eye out for potential signs of autism and developmental delays, a diagnosis can be given early. Treatment can then begin as soon as possible, and this early intervention greatly improves outcomes.

There is no cure for ASD, but it is a highly manageable disorder. With effective therapy, children with autism often grow into stable, independent, and thriving adults.

Getting a Diagnosis

Autism spectrum disorder is usually first recognized by parents and caregivers of children. This frequently happens at a young age, but it can also happen later in childhood.

The next step is usually a conversation with a pediatrician about these concerns. The child’s doctor will then perform a screening and may refer the child to a specialist based on the results.

One of the screening tools used to diagnose autism is the M-CHAT (Modified Checklist for Autism in Toddlers). It is used to spot autism spectrum disorder in toddlers between the ages of 16 and 30 months. If the M-CHAT or the M-CHAT-R/F (M-CHAT Revised with Follow-Up) shows indicators of autism, a more detailed evaluation will need to be conducted by a specialist.

The specialist will perform a more in-depth and comprehensive evaluation of the child, often with the help of a team of medical professionals. These professionals all observe if the signs and symptoms of autism are present in the child, using a variety of testing metrics. This team can include a:

  • Neuropsychologist.
  • Developmental pediatrician.
  • Speech-language pathologist.
  • Child psychologist or psychiatrist.

What Happens After Diagnosis?

If a diagnosis of autism is given, the child is then referred to early intervention and treatment services. Parents will need to work with their health insurance carriers to confirm coverage options and treatment providers.

Once coverage has been established, parents can seek out treatment providers. These providers often require prior authorization from insurance companies before providing services.

Some therapy and speech-language services are provided through local school districts in some capacity. Private trained specialists can provide even more support and behavioral interventions to help children capitalize on their strengths while learning effective coping skills for managing the symptoms of ASD.

Autism Treatment

The National Institute of Mental Health (NIMH) recommends that treatment begin as soon as a diagnosis of autism is given.

Treatment for autism spectrum disorder may include the use of medications to control certain symptoms along with behavioral interventions. Co-occurring or underlying disorders will also need to be treated in conjunction with ASD.

Therapy is specific to the individual. There is no one-size-fits-all solution, and treatment plans are tailored to each child.

Per the CDC, treatment options for ASD include:

  • Applied behavior analysis.
  • Social skills training.
  • Physical therapy.
  • Occupational therapy.
  • Assistive technology.
  • Sensory integration therapy.
  • Dietary approaches.
  • Complementary and alternative medicine.
  • Behavior and communication approaches.

One of the most notable treatment approaches for autism spectrum disorder is applied behavior analysis (ABA). This is a behavior and communication approach that capitalizes on positive behaviors through reinforcement while discouraging negative behaviors. ABA is backed by scientific research that illustrates its effectiveness, particularly for children with autism.

Targeted behavior and communication approaches can help children develop organizational skills, direction, and structure to learn how to manage ASD throughout their lives. Treatment for autism often includes simulated play and skill-oriented training sessions that can improve social interactions and skills as well as communication and language abilities.

An exact treatment plan for autism will be based on input from the family as well as recommendations from the detailed evaluation and therapy providers. ASD treatments can include office visits, in-home services, and telehealth (online) options.

Family Support

Family involvement in autism treatment is critical. It can be helpful for parents and other family members to participate in therapy sessions along with the autistic individual. They can then reinforce the lessons learned in therapy in everyday interactions.

It can be equally important for parents to engage in personal counseling on their own. Parenting a child with autism comes with many difficulties that neurotypical parents may not understand. In therapy, parents can learn to process their own feelings and acquire skills that help them best support their child.

There are also many support groups available for parents of autistic children. These can be helpful sources of encouragement, insight, and support. They are many online options in addition to in-person meetings, so parents can likely find a support group that works best for their schedule.