Understanding the Signs & Symptoms of Autism

Autism Spectrum Disorder (ASD), also known as Autism, is a developmental condition that affects people physically, emotionally, and socially. Like everyone, people with autism are born with a variety of strengths and challenges. Autism affects the way individuals communicate, behave, and engage with the world around them. Some may be able to live fully independent lives, while others may need a lot of help in their day-to-day lives. Recognizing the early signs of autism can help your loved one get the right support and intervention to navigate daily life. 

At Boundless, we emphasize the importance of identifying the signs of autism early. Early intervention provides autistic people with a better chance to thrive in their communities. 

This article will explore the signs of autism across different age groups, including core traits, behaviors, and the importance of early intervention. 

Key Takeaways:

• Autism Spectrum Disorder (ASD) is a broad range of conditions that affect how a person communicates, interacts, and experiences the world. 
• Every person with autism is unique, with their own strengths and challenges. 
• Support and intervention at any age can help individuals thrive—whether through communication tools, learning strategies, or community inclusion. It’s never too late to seek support.
• Signs of autism vary widely and include differences in social communication, behavioral patterns, and sensory experiences.
• Autism can present differently across life stages. 
• Autism can coexist with other conditions, such as anxiety or ADHD, but correlation does not equal causation.
• Supports and services like speech therapy, occupational therapy, and behavioral therapies can help individuals build skills and confidence at any age.

What Is Autism Spectrum Disorder (ASD)?

Autism Spectrum Disorder is a developmental difference. Developmental disorders impact how children grow and learn, affecting their physical abilities, thinking and communication skills, language, and behavior. 

The term “spectrum” refers to the wide range of abilities, behaviors, and challenges that people with autism experience. The support needs vary from individual to individual. 

Some common features of ASD include: 

• Differences in communication and social interaction: people with autism may communicate in unique ways or interpret social cues differently. 
• Repetitive behaviors and focused interests: engaging in routines or hyperfocusing on particular interests. 
• Sensory sensitivities: some people experience the world more intensely, including sensitivity to lights, sounds, textures, and other stimuli that others may overlook. 

Though the causes of Autism Spectrum Disorder are not fully understood yet, genetics and environmental factors play a big role in its development. Advances in research and diagnostics have made it easier to identify autism, even early in childhood. 

What are the common signs and symptoms of Autism Spectrum Disorder?

Each person with autism is unique. It’s important to keep in mind that symptoms and behaviors vary from person to person, and no two individuals are the same. 

Dr. Stephen Shore once said, “If you’ve met one person with autism, you’ve met one person with autism.” No two people will have the same signs and symptoms, but there are some common signs.

Common Social Communication Challenges:

• Interpreting social cues like body language or facial expressions
• Keeping up with conversations or engaging in back-and-forth interactions
• Forming and maintaining relationships
• Eye contact
• Sharing interests with others
• Using gestures when communicating

Common Behavioral Patterns:

• Repetitive movements like hand-flapping, spinning, or rocking (Stimming)
• Strong need for routines
• Discomfort when the routine changes
• Trouble with transitions from one activity to the next
• Intense interests in specific topics, objects, or activities
• Repeating words or phrases constantly (Echolalia)
• Reacts unusually to sounds, smells, tastes, looks, or feelings
• Talking fast, loud, or not talking at all

Common Sensory Experiences:

• Heightened sensitivity to loud noises, bright lights, and certain textures (clothing, food)
• Unusual responses to stimuli (like covering ears or avoiding certain types of fabrics)
• Difficulty identifying sensations like hunger or pain

Recognizing and understanding these characteristics can help families, educators, and communities provide better support and create more inclusive environments.

Early Autism Signs in Children

Detecting Autism Spectrum Disorder in your loved one can be a challenge. Early detection allows parents and family members of children with autism to intervene early by partnering with the right autism care clinician. This can significantly improve the way a child develops socially and cognitively and communicates with others. 

Many signs of Autism can be seen by 18 months, but some might not become apparent until later. Common early signs at this age are: 

• Delayed speech development
• Limited or no response to their name being called
• Avoids eye contact
• Doesn’t use gestures or uses them very sparingly
• Does not show facial expressions (surprise, happiness, sadness)
• Prefers to play alone or limit social interaction with their peers
• Difficulty sharing their interests with others
• “Stimming” or repetitive movements like rocking or hand-flapping.
• Trouble engaging in pretend or make-believe play or simple interactive games
• Sensitivity to sensory stimuli (noise, lights, textures)
• Trouble knowing when others are hurt or upset

Early support and intervention, like behavioral and speech therapy, can help loved ones with autism develop the life skills they need to function on a day-to-day basis.

Signs & Symptoms of Autism in Teens

When a person with Autism Spectrum Disorder faces their teenage years, social expectations, pressure from their learning environments, and interactions with their peers are more challenging. Teens with autism experience more stress, confusion, and anxiety, which affects their interactions and behavior. 

Some teenagers may try to “mask” or hide their autism traits in an effort to fit in, making it harder to recognize the signs. Some signs and symptoms of autism during adolescence include: 

• Difficulty understanding sarcasm or humor
• Difficulty understanding subtle social cues
• Trouble managing group conversations 
• Trouble keeping friendships
• Literal interpretation of language, leading to misunderstandings (for example, they may take “keep an eye on your desk” literally)
• Discomfort in highly social environments
• Reliance on “scripts” to navigate social interactions
• Repetitive or compulsive behaviors 

Teenage years are difficult, especially for people with autism. A compassionate, understanding approach to identifying ASD in adolescents is the core of Boundless Health’s approach to autism care. 

Signs & Symptoms of Autism in Adults

While many individuals with autism are diagnosed in childhood, some might not receive one until adulthood. In adults, signs and symptoms can be more subtle or masked, especially if you or your loved one has learned coping strategies. 

Many adults with autism lead fulfilling lives, whether diagnosed early or later. Some may have learned coping strategies that make signs less obvious, like mimicking social cues or generally avoiding situations that might make them uncomfortable. Recognizing the signs in adults is more difficult, but they align with those in childhood and adolescence: 

• Difficulty understanding and reading social cues (tone of voice, body language, subtle facial expressions)
• Finds casual conversation challenging and making and maintaining friendships even harder. 
• Prefers a predictable routine
• Trouble using gestures to express themselves
• Literal interpretation of language
• Self-soothing behaviors or “Stimming” (hand-flapping, repetitive speech, rocking)
• Feeling overwhelmed by bright lights, loud sounds, crowds, or textures

Despite these challenges, many adults with autism have strengths in areas like problem-solving, attention to detail, and expertise in specific interests, which can contribute positively to both personal and professional life.

Boundless does not provide adult autism assessments, but many of our services can benefit undiagnosed adults with ASD. Counseling and other types of therapy can help without the need for a formal diagnosis. 

Co-Occurring Conditions 

Autism does not exist in a vacuum. It may coexist with other conditions like anxiety or ADHD, but it’s important to know that autism is unique to every individual. Anxiety may be caused by autism to some extent, but other reported conditions, like epilepsy, don’t have not been sufficiently researched for a solid conclusion. 

Correlation does not equal causation. 

Unique Strengths

Autism isn’t just about challenges—it often comes with incredible strengths that enrich families, communities, and workplaces. Many people with autism show exceptional abilities such as:

• Remarkable attention to detail
• Exceptional memory
• Creative problem-solving skills
• Deep expertise in their topics of interest
• Ability to hyperfocus and achieve mastery in chosen topics

The Importance of Early Detection & Intervention

Early support and intervention can help individuals with autism build skills and reduce challenges. Not because autism needs to be “fixed,” but because every person deserves tools to succeed. People with autism who have been diagnosed early show improved outcomes in communication, socialization, and academic success. 

Early intervention can include behavioral, speech, and occupational therapy. 

At Boundless, we remind families that while early intervention helps tremendously, it’s never too late to receive a diagnosis. 

Autism Doesn’t Exist in a Vacuum

Understanding the signs and symptoms can help individuals and families get the support they need. Autism Spectrum Disorder is unique to every person, and support and recognition are important for their social and personal development. 

Early detection is important, but it’s never too late to be diagnosed or seek support. 

Embracing neurodiversity allows our society to benefit from the unique perspectives and talents that people with autism bring. Advocating for them and creating inclusive communities leads to greater acceptance and support. At Boundless, we advocate for acceptance, inclusion, and love—because every person deserves to live a life full of dignity and opportunity.