How to Recognize Borderline Autism in Adults and When to Get Tested

You may have heard the phrase “borderline autism” — often used to describe adults who relate to some autism traits but don’t meet every criterion for a formal diagnosis. 

While “borderline autism” isn’t an official medical term, it’s a phrase many people use to make sense of their experiences. So what does it actually mean?

What is Borderline Autism?

“Borderline autism” typically refers to adults who show several signs of autism but may not fully meet the diagnostic criteria for Autism Spectrum Disorder (ASD).

Some people might have mild or subtle traits that affect social interactions, communication, or sensory processing — but they’ve learned to mask or adapt over time.

These individuals might:

• Find social situations exhausting or confusing
• Prefer routines or have strong interests
• Experience sensory sensitivities (noise, light, textures)
• Struggle with change or emotional regulation

Because autism exists on a spectrum, some adults fall near what people informally call the “borderline.” But even mild traits can impact daily life and relationships — which is why understanding them can make a real difference.

Why Borderline Autism Can Be Overlooked

Many adults, especially women and late-diagnosed individuals, go through life without realizing they may be autistic. Some common reasons include:

• Masking: Hiding or suppressing autistic traits to fit in socially.
• Misdiagnosis: Being diagnosed with anxiety, ADHD, or depression instead.
• Lack of awareness: Growing up before autism was widely recognized or diagnosed in adults.

If this sounds familiar, it’s not too late to explore your experiences. A professional autism evaluation can help you understand whether autism — or something else — is contributing to the challenges you face.