Signs of Autism (Early Autism Signs & Markers) - Acorn Health

July 14, 2021

Signs of Autism

Understand the most common red flags of autism and what to do next 

Do you have concerns about your child’s development? As your toddler develops new skills, it can be difficult to decipher what is considered normal development and when to seek professional guidance. Typically, initial signs of autism can be present between 2 and 3 years old, but some children can be diagnosed as early as 18 months old. Understanding common signs and characteristics of autism can help parents and caregivers lead their child toward a fulfilling and independent life by providing intervention as soon as possible. 


Over the last decade, autism has become more widely known and understood between parents and medical professionals. Current estimates show that autism affects 1 in 54 children. It’s defined as a neurodevelopmental disorder characterized by social, cognitive and communication deficits. For caregivers, the disorder can be very confusing and difficult to navigate since everyone’s experiences can vary so widely. It is a lifelong spectrum disorder; meaning individuals with autism can have very different challenges and strengths. What we do know is that early intervention is incredibly important, and leads to positive outcomes and earlier progress for children and their families. 

Early signs of Autism Spectrum Disorder

It can help to understand what the earliest signs and markers of autism include. The lists below are meant to illustrate some of these symptoms, but not necessarily all of them. If you believe your child is presenting some of these signs, reach out to your pediatrician with questions. 


  • Not responding to their name 
  • No speech or delayed speech 
  • Reversing pronouns 
  • Stopped saying words they used to say 
  • Frequently repeating words or phrases they’ve overheard 


  • Not playing pretend 
  • Pointing without looking to someone else to share the experience
  • Avoiding eye contact 
  • Exhibiting symptoms of extreme anxiety 
  • Obsessive interests 
  • Impulsivity or hyperactivity 
  • Developed rituals like lining objects up or organizing items 
  • Highly restricted interests
  • Restricted or repetitive behavior patterns
  • Lack of communication skills 
  • Social or friendship challenges 
  • Highly restricted interests 


  • Hand flapping or spinning in circles  
  • Obsessive sensory interests such as sniffing objects or materials 
  • Displaying strong, disruptive reactions to loud noises 
  • Poor coordination 
  • Eating difficulties or extremely picky eating 


Signs of autism vary widely by child, as do when those signs appear in the child’s development. Below we have outlined common ages when autism spectrum disorder early signs first appear. While some children demonstrate these signs as early as their first few months of life, others may not until their toddler years.

Regardless, if you have concerns about your child’s development, ask your pediatrician. Currently, all children are routinely screened for autism at 18 and 24 months during their pediatrician well visits. There are multiple screeners, one of the most common tools is called the M-CHAT, or Modified Checklist for Autism in Toddlers, which is a 23-point questionnaire designed to identify if your child has a probability of being diagnosed with autism. If your child demonstrates a high probability of being diagnosed with autism, your pediatrician will refer you to additional specialists for testing.

Below is a guideline of common signs of autism spectrum disorder by age:


  • Limited eye contact
  • Few smiles or warm expressions


  • Does not play interactive games like pat-a-cake
  • Limited back and forth sharing of expressions, smiles, babbling
  • Does not respond to their name
  • Little babbling
  • Uses few gestures such as hello or goodbye


  • Little talking
  • Does not point to show you something of interest
  • No speaking in two-word phrases
  • Little interest in playing with others
  • Prefer to be alone


  • Loss of previously acquired speech or babbling
  • Avoiding eye contact
  • Repeating words or phrases (echolalia)
  • Restricted interests
  • Lining up toys and getting upset when a peer or caregiver changes the order
  • Obsessive interests or routines
  • Repetitive behaviors like flapping, spinning, walking on toes, or rocking

Is Autism Spectrum Disorder Suspected?

Visiting the pediatrician for well-checks, especially in those first early newborn months, can be exciting to see how many pounds or inches your baby gains each visit. As your baby grows, your pediatrician will start asking about his/her or their specific developmental milestones. If you have questions or begin to worry that your child isn’t developing in the same way as his or her peers, it can be concerning.  

If atypical development points towards potential Autism Spectrum Disorder (ASD) warning signs, begin conversations with your doctor about diagnostic options. At 18 and 24 months, the American Academy of Pediatrics recommends that all children are screened for autism.  Whether the signs were noticed during a well-check by the pediatrician, or certain behaviors (or lack of) have been a recent cause for concern, obtaining answers and a diagnosis are the first steps toward feeling in-control and helping your child.  


If you are a concerned parent, there are many resources available to provide you with answers. Typically, screening tools can be used between 16 and 30 months old, and the American Academy of Pediatrics (AAP) recommends that all children receive autism screening between 18 and 24 months of age. Local diagnostic resources, financial options, counseling, scholarships and therapy services are typically available for families. Reach out to your local or state department of health to see what is available.

If you notice some of the warning signs listed in your child over time, consult with your child’s pediatrician first to rule out any underlying causes. Because these symptoms could indicate a vast number of conditions, either neurological or physical, medical professionals can determine if an in-depth psychological evaluation is indicated. While teachers, daycare workers, speech therapists and others are important stakeholders in your child’s development, they are unable to fully diagnose ASD. A full psychological diagnostic evaluation will need to be completed by a licensed medical professional. Psychologists, psychiatrists and neurologists in your area may offer ASD diagnostic testing as part of their medical practice. Your insurance company may also be able to help connect you with medical professionals in your area offering diagnostic services. 

As you begin the steps to obtain a full evaluation, you can still receive services related to your child’s developmental delays through local programs. Reach out to your state and/or school district’s Early Intervention Programs to learn more about what is offered. Initial services are extremely beneficial for your child, even before an autism diagnosis is obtained. If your child is diagnosed with Autism Spectrum Disorder, they will likely qualify for many additional services.   

There are two critical psychological tests your child will need, the Autism Diagnostic Observation Schedule, SECOND EDITION (A-DOS-2) and the Autism Diagnostic Interview, REVISED (ADI-R). Additionally, several other psychological assessment measures and clinical questionnaires can be utilized to clarify many aspects of your child’s development and level of functioning.   

At several of Acorn Health’s locations we are able to clarify psychological diagnostic concerns with an initial Telehealth session, which typically lasts two hours and, if indicated, an additional office-based session will be scheduled that lasts approximately three hours. We understand that you will want to know the results as soon as possible, so feedback regarding the diagnosis will be provided at the end of the evaluation sessions and you can expect to receive a written report within one week. 

If you’re in another area outside of where Acorn Health provides diagnostic testing for autism, we recommend the following:  

  • Consult with your pediatrician on local diagnostic testing resources 
  • Contact your insurance company for local options based on your insurance plan 
  • Contact your local health system or autism resource center 
  • Research clinical psychologists, psychiatrists and neurologists that may offer ASD diagnostic services

*Please note that if you are in a rural area of the country it is not uncommon to have to travel to another area of your state to receive an ASD diagnosis. 


After an autism diagnosis is received, there are many powerful treatment options. A multi-disciplinary approach to treatment, including Applied Behavior Analysis (ABA) would likely benefit your child. Acorn Health specializes in providing high-quality ABA services. The Acorn Health admissions team will work with your family to provide information about what to expect with ABA therapy and how to enroll your child for services. An official ASD diagnosis is required by insurance companies in order to start services. The sooner your child begins receiving therapy, the sooner they can begin making progress, reduce problem behaviors, and develop the skills that will help them be more successful in educational settings, at home, and later in life.


Acorn Health is proud to be a trusted resource for families and caregivers affected by autism. Additionally, there are helpful online resources we recommend that you read through to gain more knowledge about the complex diagnosis of autism: 


Once you have received an autism diagnosis, we recommend getting an assessment for ABA therapy as soon as possible to learn how ABA can benefit your child. Learn more about the value of early intervention ABA therapy here. Additionally, evaluations by a speech therapist and an occupational therapist can be helpful for some children to address communication challenges and physical challenges they may be experiencing. Here at Acorn Health, we collaborate with many other providers and therapists in the treatment of children with autism.

Frequently Asked Questions

What are some signs of high functioning autism?

Some signs of high functioning autism include social adaptability issues, obsession with routines, emotional hypersensitivity, and inability to change.

What are the early warning signs of autism?

Early warning signs usually involve parental concerns around a child's social skills, lack of communication, or repetitive behavioral patterns.

Can a child show signs of autism and not have it?

Yes, some children who don't have autism will still display signs of it. Most autism diagnoses aren't done until the age of 4 or 5.