Why is autism missed in girls?

Autism is often missed in girls because diagnostic criteria were built around boys and many girls mask their traits to fit in, so their difficulties get put down to anxiety, shyness or puberty instead.

Why recognition slips

The picture most people carry of autism, and the tools clinicians use to spot it, were drawn from studies of boys. Girls who do not match that picture get overlooked. The National Autistic Society points to a few reasons this happens again and again:

• Masking. Many girls learn to copy other children, script conversations and hide their differences. It is exhausting, and it hides the traits from teachers, GPs and assessors.
• Interests that look ordinary. An intense focus on books, animals or a single friendship can read as a typical girl's hobby rather than as an autistic interest, so it never raises a flag.
• Wrong labels. The struggle often gets named as anxiety, depression or an eating disorder, or written off as shyness, puberty or hormones, while the autism underneath goes unrecorded.

The part most accounts miss

Here is the qualifier that changes how you read your daughter. The evidence does not clearly show that autism presents differently in girls so much as that it is recognised differently. Girls appear to need more added difficulties, more behavioural or emotional problems, before clinicians notice the same level of autistic traits they would spot in a boy. So "she makes eye contact, she has a friend, she does well at school" is not evidence against autism. Those can be the mask.

That under-recognition shows up in the numbers. A study of more than seven million pupils in England found autism diagnosed about four times more often in boys than girls, yet community studies that go looking for undiagnosed children put the true ratio closer to three to one (Lancet Child & Adolescent Health, 2022). The gap is girls being missed. A separate analysis of English health records estimated that most autistic people are still undiagnosed, with women and older people the most likely to be overlooked (Lancet Regional Health – Europe, 2023).

Why it matters, and what you can do

A missed diagnosis is not a tidy gap. It is linked to poorer mental health, including anxiety, depression, low self-worth and a higher risk of self-harm, because a child spends years feeling different without knowing why. If your daughter is anxious, avoiding school, exhausted or low, that is a reason to ask the question, not a reason to assume autism has been ruled out.

You do not need to wait for the school or GP to suggest it. You can ask for an assessment yourself. If your daughter is in immediate danger or talking about ending her life, call 999 or go to A&E. For ongoing worry, you can raise it with the GP or school directly. Our siblings on what masking in autistic girls looks like, what autism looks like in girls and how to get your daughter assessed cover each step.

This page is general information, not clinical or legal advice.