3 Levels of Autism: Symptoms, Diagnosis & Life Expectancy

Today we’ll explain what the three levels of autism spectrum disorder are, their differences, and similarities.

steven zauderer
Steven Zauderer
November 9, 2023
min read

What Are The 3 Levels Of Autism?

The three levels of autism, as per the DSM-5, are Requiring Support, Requiring Substantial Support, and Requiring Very Substantial Support.

Each of these three levels is detailed in the manual. Furthermore, all persons receiving an autism diagnosis can be diagnosed even further according to the level they present. This is predicated on how strong the symptoms are and the level of support they would need in their day-to-day lives.

3 functional levels of autism
Source: VeryWellMind

Every level is arranged where the least severe begins at level 1, and the more severe ends at level 3. There are no higher levels than the levels that are listed.

Level 3 is descriptive of someone that has the most extreme qualities found within Autism Spectrum Disorder. Level 1 is the opposite, being descriptive of a person with the mildest symptoms.

levels of autism
Source: PsychCentral

Level 1 Autism: Requires Support

A person that falls within the category of Level 1 will have social issues that do mandate some level of assistance.


  • Difficulty in starting up conversations - Socializing can be a challenge for anyone with autism. This is true for the Level 1 category as well. It's descriptive of someone not having the capacity to engage with other people in a normal fashion, oftentimes leading to shyness or introversion. Talking might be easier to do around family and other siblings, but strangers tend to be shied away from it. Additionally, having problems talking can morph into other problems if one isn't provided therapy to make them more sociable. Still, many with autism find it hard to dialogue, even those that are highly functioning.
  • Problems responding in ways that are expected - When someone with ASD does talk with another person, the response may not be what others around thought that it would be. What's spoken may come out as awkward at best, or indifferent at worst. Then there are issues with the autistic saying things that others don't understand, or might even find rude.
  • Problems staying with a conversation - Conversations are hard for the autistic, but many do try to have them. In the instances that they do, there could be an abrupt pause or disinterest in where it's going, then indifference.
  • Problems making friends - Although more know and understand what autism is, people that have it often struggle with friendships that are outside of the family. Their actions and demeanor can appear odd, or sometimes, off-putting to people that try to initiate conversation. When awkwardness is a factor, people generally shy away from it, and that's what makes it hard to form bonds with peers and co-workers.
  • Requires help in organizing - Mild symptoms usually involve a need for assistance organizing. This may or may not apply to personal hygiene. But more common organizational problems revolve around help in cleaning one's room, arranging toys, clearing away decks, and properly arranging clothing and shoes.


A diagnosis for Level 1 autism can range from fast to slow. Because of the mild symptoms, more psychiatrists may become concerned about a misdiagnosis with other similar disorders.

Mild autism can resemble things like ADHD and Social Anxiety Disorder, so extended tests could come after the initial. However, the most likely scenario is few tests, such as mild ASD is manageable, especially when Applied Behavior Analysis is done.

To complete a diagnosis, psychiatrists will take on interviews with subjects to see how well engaged they are in eye contact, socializing, and repetitive actions. From there, a diagnosis is made with a small period of ABA usually being recommended.

Life Expectancy

The life expectancy for people in the category of Level 1 ASD is the highest among the three. It's slightly lower than the average life expectancy, but the lack of extreme symptoms means that most having the disorder are capable of carrying a normal life.

Of course, some therapy could help, but this is generally prescribed to Level 1 patients with awareness of these mild symptoms. It wouldn't take long for them to finish, even childhood, then later go about their lives.

Level 2 Autism: Requires Substantial Support

At Level 2 autism, there's a noticeable higher need for support regarding one's symptoms that extends greater than what's required for Level 1. Talking and being social is very difficult at this stage. Support may come but it won't guarantee success in social abilities.

Additionally, responses will be odd and off-putting, or even inappropriate. Poor manners might be a feature, along with other moderate ASD symptoms related to stimming.


  • Speaking in small sentences - Although talking might not happen very often, it usually revolves around very short sentences. When done, the answers and responses could be to the point, unclean, or need extra context to fully understand.
  • Specific topics are discussed only - This tends to happen when the topics involve things they're interested in. If the topic isn't of interest, they might say little to nothing, even when they're encouraged to do it.
  • Problems with nonverbal dialogue - One of the most common is facial expressions. Facial expressions exist for humans to understand people without words being exchanged. Unfortunately, many with autism cannot do this properly. The condition was once described as Asperger's but is associated with Level 2 autism now. When someone is talking to them, they may engage in actions that appear rude or disinterested. A person on the spectrum, for instance, may turn their back toward someone immediately after they begin to strike up a conversation with them, even if they do manage to say a few words or turn around, they possibly would have trouble understanding the context behind what's said.
  • Problems with daily routines - Change doesn't always come easy to people with autism. When things do change, They usually end up becoming negative for people on the spectrum. Changes that lead to problems aren't always the same. Some might detest having to move their desk in a classroom to a position that places them in the center of everyone's attention. Their family might be planning a move away from the home that an autistic person loves and is adjusted to.


Level 2 autism is diagnosed by reliance on more extensive interviews, possibly even a brain scan. MRIs can find abnormalities in the brain, such as areas of matter that are larger than they typically are.

Tests might be run on the digestive tracks for signs of infections along the large intestine's lining. This could follow up with therapy, though the diagnosis might be done at another location.

Life Expectancy

The life expectancy for Level 2 ASD ranges from 50-60 years old. This is slightly lower than Level 1 and the national average. In some studies, the life expectancy is even lower.

The factors that can contribute to a shorter life are injuries to self, injuries stemming from unawareness, trauma, and suicide. The more people that are available to assist people at this level, the greater chance they'll have a long and fulfilling life.

Level 3 Autism: Requires Very Substantial Support

Level 3 autism requires more support than the others, and for longer periods. People in this category exhibit strong difficulty in understanding communication, both verbal and nonverbal.


  • Limited interaction with other people - They'll show little to no desire to talk to anyone or engage with people in any way. This may include family members. Most of the time, they'll want to be left in solitude and entertain themselves with toys, games, and sometimes things that might not appear to be entertaining at all.
  • Little to no imagination - Children usually think outside the box and use much imagination when they play with action figures and games. This comes incredibly hard at Level 3 autism. So hard in fact, that they might refuse to interact with peers or even siblings.
  • No interest in friendship - Friendship wouldn't be sought out by people on a spectrum at this level. So most of their time will be spent on their interests. Forming friendships with other children might seem as scary and could even cause one to engage in poor behavior when pressed. Some of the behavior should be very intense, which could also make it hard to foster friendships with their peers.
  • Problems with changing routines - When a routine is attempted to be changed, a strong negative reaction might occur. Taking a toy away from them, making them clean up things that they usually don't do, and going out somewhere they've never been before causes them great agitation, or even anger. And during this stage, head banging and pulling at the skin may happen.
  • Lots of repeating behavior patterns - Level 3 autism is characterized by numerous emotions, and one is behavioral issues that happen numerous times. They may flip random objects, including their toys but also things that shouldn't be played with. It can get repetitive to a level that causes a total inability for them to function normally.
  • Marked stress - Stress is triggered at this stage very easily. The main causes of it are being in a situation where they must focus on something they don't want to pay attention to, like a class setting with a teacher. But this can happen to them on their own as well, even with their parents. Task performance, even for things that appear easy, may be interesting at first, then morph into boredom, then end in distress when they must continue to do it.


A diagnosis for Level 3 autism could come easier than the other level since the symptom tends to be stronger and more pronounced. It might also come at an earlier age. They tend to be diagnosed at earlier ages, even during infancy.

However, this refers to their original autism diagnosis and not the additional Level 3. Doctors will examine to check for signs like lacking social awareness, frequent tantrums, and nonverbal communication.

Life Expectancy

Level 3 autism has a lower life expectancy. Since this is the most severe category of them all, events and changes in the body can happen that harm their risk of having a long life.

In some estimates, the life expectancy for Level 3 is 35 to 40 years old. When given extensive treatment, however, there's a possibility of it being extended.

Limitations Of Autism Levels

ASD levels make it easier for a proper autism diagnosis to be made. Still, they don't fully describe all of their limitations.

They don't include every symptom that can occur, nor do they take into consideration the varied personalities of people with the disorder. In the DSM-5, there isn't much detail about the levels of support required when recommended.


What are the different levels of autism?

The first is Level 1, which requires support. The second is Level 2, where more support is necessary to properly handle symptoms. Level 3 is the highest and requires the most support since symptoms are extreme. The three levels of autism vary depending on the child's age, symptoms, environment, and more.

What is the most severe level of autism?

Level 3 is the most severe level of autism. It also requires the most resources to assist and prolonged time spent in therapy.

Can level 1 autism be cured?

No, there's no cure for Level 1 autism. The only way that one can see symptoms reduce is through treatment.

Can level 1 autism be cured?

Some on the spectrum characterized as high functioning start at this level, then reduce their symptoms gradually until they can manage it all on their own. But even in this situation, their previous symptoms can return.

Can level 2 autism be cured?

Level 2 autism cannot be cured. It's also harder to reduce symptoms, yet not impossible either.

Can level 2 autism be cured?

Can level 3 autism be cured?

Like Levels 1 and 2, the third has no way of being entirely cured. Autism is a condition that can never be eliminated by the means currently used to treat it.

Can level 3 autism be cured?

Do children with level 1 autism need a classroom aide?

Sometimes they do but they can manage to properly conduct themselves in a classroom setting. Behavioral therapy is a great tool to help them achieve this.


No matter what level is present in someone with an autism diagnosis, they're most likely to get the most out of treatment when there are people around that understand them. The issue might persist for a long time, but it's certainly possible for all with ASD to grow in the areas they usually lack.

steven zauderer

CEO of CrossRiverTherapy - a national ABA therapy company based in the USA.

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