Autism is a disorder that is usually diagnosed in early childhood. The main signs and symptoms of autism involve communication, social interactions and repetitive behaviors.
Children with autism might have problems talking with you, or they might not look you in the eye when you talk to them. They may spend a lot of time putting things in order before they can pay attention, or they may say the same sentence again and again to calm themselves down. They often seem to be in their "own world."
Because people with autism can have very different features or symptoms, health care providers think of autism as a "spectrum" disorder. Asperger syndrome is a milder version of the disorder.
The cause of autism is not known. Autism lasts throughout a person's lifetime. There is no cure, but treatment can help. Treatments include behavior and communication therapies and medicines to control symptoms. Starting treatment as early as possible is important.
NIH: National Institute of Child Health and Human Development