"High-functioning autism" (HFA) is a term used to describe people with a certain level of autism spectrum disorder (ASD). They have milder symptoms and fewer challenges than those with more severe ...

Mild autism is unofficially used to describe level 1 autism, or high-functioning autism. People with mild autism might not get diagnosed until adolescence or adulthood because their traits are subtle.

Readers weigh in on the challenges of defining and diagnosing the condition. To the Editor: Re “In New Focus on Autism, Some Worry the Spectrum Is Too Broad” (front page, Oct. 5): One thing’s for ...