Low Functioning Autism: Symptoms and Therapies

Reviewed by:
Hannah Andreasen

April 29, 2022

Low functioning autism, or LFA, refers to children and adults who display the most severe symptoms of autism and face challenges living independently.

Children with low-functioning autism are often unaware and unable to understand the consequences of their actions. This unawareness can have severe consequences for their safety such as engaging in self- injurious behaviors or aggression towards others.

The three levels of ASD

Autism disorder is a spectrum and contains three levels:

  • Level 1 — Individuals with level one autism have mild symptoms which have minimal interference with their daily lives.
  • Level 2 Individuals with level two autism need some support in working on communication, social skills and behavioral deficits.
  • Level 3 — Individuals with level three autism will require extensive support, which might involve intensive therapy.

Low functioning autism

Children classified under low functioning autism find it challenging to manage their everyday life activities. These children also face behavioral issues and cognitive difficulties across activities. 

Along with this, the children typically have restrictive, stereotypic, and repetitive behavior, such as hand flapping or rocking. Children with low functioning autism may find it difficult to learn in the traditional classroom and develop relationships.

Communication is especially difficult for these individuals.  They may have trouble communicating verbal or their speech may consist of echolalia or repetition, they often get upset or frustrated when unable to express themselves properly. The most common behaviors of low-functioning children with autism may include:

  • Self-injury (hitting or biting themselves)
  • Self-stimulation (flapping hands, walking in circles, or spinning around)
  • Over-reactivity to changes
  • Inappropriate responses
  • Sensory disturbances
  • Aggression towards others

Children suffering from low-functioning autism typically have a low IQ (below 80). However, despite their low IQ, some may have exceptional skills and talents called savant skills.

Typical symptoms of low-functioning autism

Here are a few symptoms that can be seen in low-functioning children with autism:

  • Difficulties with social interaction
  • Inappropriate reactions in many situations
  • Slow speech development
  • Repetitive behaviors
  • High anxiety levels
  • No interest in interacting with other people
  • Difficulty sleeping
  • Inability to communicate their needs like hunger, tiredness, thirst, etc
  • Disliking loud noises, bright lights, and other intense sensory disturbances
  • Emotional outbursts
  • Difficulty with changing daily routines
  • Avoidance of leaving comfort zones
  • Lack of social skills
  • Lack of empathy
  • Lack of impulse control
  • Lack of facial expressions
  • Incorrect speech patterns
  • Intellectual disabilities
  • Dislike of physical touch

How does low-functioning autism differ from high-functioning autism?

Children with level 1 autism have high functioning autism, whereas children with level 3, are categorized with low functioning autism. Below are some of the common differences:

  • Children with high functioning autism can have healthy relationships and live independently, whereas children with low functioning autism find these things difficult or require life-long assistance.
  • Some high-functioning children with autism may be aggressive, while some low-functioning children with autism may not.  Each child and diagnosis is different. 
  • High functioning children with autism can typically learn traditionally and interact with others while low functioning children with autism require more substantial support.

Diagnosis and therapies for low-functioning autism

A child's early development age is crucial for their future learning and growth. As a parent, you are responsible for supporting your child as they develop. For all children with autism, early intervention and diagnosis have been shown to have a significant impact on the child’s development and increase the chances of successful outcomes.

Here are some of the therapies that can help children with autism at level 3:

Augmentative and Alternative Communication (AAC)

AAC is a therapy used for children with autism who face difficulty in communicating. Here, the children are taught to use different forms of communication such as sign language, Picture Exchange Communication System (PECS) or a Speech-Generating Device (SGD).

Speech-Language therapy

Speech-language therapy helps children with autism who need to develop their communication skills. It is designed to facilitate the coordination of the different mechanics of speech and help children communicate more effectively.

Occupational therapy

Occupational therapy helps children with autism learn and integrate everyday activities such as personal hygiene.

Sensory integration therapy

Sensory integration therapy helps children with autism adapt to different kinds of sensory disturbances and react calmly outside of the therapy setting.

Applied Behavioral Analysis (ABA)

ABA therapy is considered the golden standard of therapies for children diagnosed with autism. This therapy focuses on improving the child's behaviors around social skills, play skills, and communication skills and can help children overcome problematic behaviors such as self-injury or aggression.

All therapies are tailored to the unique circumstances of each individual and can help with all levels of functioning. In-home therapies, such as Songbird, provide a safe, familiar and comfortable  for you and your child.


Low-functioning children with autism can face unique challenges in their lives. Early intervention through ABA therapy increases the success rate of living an independent lifestyle. 

Songbird Therapy is a technology-enabled provider setting a higher standard for children’s autism care. With a deeply passionate team and innovative technology, we’re building a world where every child can access world-class care at home, uniquely tailored to them.