Autism spectrum disorder - Symptoms and causes - Mayo Clinic
Autism spectrum disorder is a condition related to brain development that affects how people see others and socialize with them. This causes problems in communication and getting along with others socially. The condition also includes limited and repeated patterns of behavior.

Autism - Wikipedia
Autism is primarily characterized by differences and difficulties in social interaction and communication, alongside restricted or repetitive patterns of interests, activities, or behaviors (stimming), and, in many cases, distinctive reactions to sensory input.

Signs and Symptoms of Autism Spectrum Disorder
Autism spectrum disorder (ASD) is a developmental disability caused by differences in the brain. People with ASD often have problems with social communication and interaction, and restricted or repetitive behaviors or interests.

What is Autism? - Autism Research Institute
Autism is a developmental disorder with symptoms that appear within the first three years of life. Its formal diagnostic name is autism spectrum disorder. The word “spectrum” indicates that autism appears in different forms with varying levels of severity.

Autism spectrum disorder (ASD) | Autism Speaks
Autism, or autism spectrum disorder (ASD), refers to a broad range of conditions characterized by challenges with social skills, repetitive behaviors, speech and nonverbal communication.

Autism: Symptoms, Causes, Types, and Testing - WebMD
Know about autism, including its symptoms, causes, types, and testing methods. Explore WebMD's comprehensive guide to better understand and manage autism.

Autism Spectrum Disorder - National Institute of Mental Health (NIMH)
Autism spectrum disorder (ASD) is a neurological and developmental disorder that affects how people interact with others, communicate, learn, and behave. Although autism can be diagnosed at any age, it is described as a “developmental disorder” because symptoms generally appear in the first two years of life.

What is autism - National Autistic Society
What is autism? Autism influences how people experience and interact with the world. It is a lifelong neurodivergence and disability. Autistic people are different from each other, but for a diagnosis they must share differences from non-autistic people in how they think, feel and communicate.

What is autism spectrum disorder? - Harvard Health
Autism spectrum disorder (ASD) is a complex neurological condition that affects how a person interacts, communicates, and experiences the world. Learn about its symptoms, causes, diagnosis, and support strategies across all ages.

Autism - World Health Organization (WHO)
Autism spectrum disorders (ASD) are a diverse group of conditions. They are characterized by some degree of difficulty with social interaction and communication.