High pain tolerance is recognized as one possible feature of autism spectrum disorder, listed explicitly in the DSM-5 diagnostic criteria. But the relationship between autism and pain is more complex than a simple “yes.” Recent research suggests that many autistic people may actually experience pain more intensely than average, while expressing it differently, creating an appearance of high pain tolerance that doesn’t always reflect what’s happening internally.
What the Diagnostic Criteria Say
The DSM-5 includes sensory differences as a core feature of autism. Specifically, criterion B4 references “hyper- or hypo-reactivity to sensory input,” and lists “apparent indifference to pain/heat/cold” and “high tolerance for pain” as examples. This means that reduced pain reactivity is officially recognized as something clinicians look for when evaluating autism, alongside other sensory patterns like aversion to certain textures or fascination with lights and movement.
That said, no single trait on its own indicates autism. A high pain tolerance would only be meaningful as part of a broader pattern that includes differences in social communication and restricted or repetitive behaviors. Plenty of people without autism have high pain thresholds, and plenty of autistic people are extremely sensitive to pain.
How Sensory Processing Differs in Autism
Sensory processing differences affect somewhere between 45% and 96% of autistic people, depending on how researchers measure them. These differences don’t fall neatly into one category. Most autistic people experience a mix of hypersensitivity (over-responsiveness) and hyposensitivity (under-responsiveness), sometimes to different types of input at the same time.
This means the same person who can’t tolerate fluorescent lights or the texture of certain fabrics might also fail to notice a cut or burn. The same child who covers their ears at moderate noise levels might seek out intense physical pressure or not react when they bump into something hard. This combination often confuses parents and clinicians, but it reflects how differently the autistic brain can filter and prioritize sensory information.
Hyposensitivity to pain can look like a constant need for movement, difficulty recognizing hunger or illness, or a muted reaction to injuries that would make most people flinch. In children, it sometimes shows up as a lack of crying after falls or an apparent unawareness of temperature extremes.
Pain Sensitivity vs. Pain Expression
One of the most important distinctions in this area is the difference between how much pain someone feels and how they show it. Research increasingly suggests these are two separate things in autism, and confusing them has led to widespread misunderstanding.
A study using the Non-Communicating Children’s Pain Checklist found no significant differences in everyday pain experiences between children with and without autism. Children in both groups appeared to encounter similar levels of pain in daily life. However, as autism symptom severity increased, parents rated their children’s pain expressions as lower. In other words, autistic children with more pronounced traits were less likely to show pain in ways their parents recognized, not necessarily less likely to feel it.
This finding supports a framework where autistic people may have typical, or even heightened, pain sensitivity, but their outward expression of pain differs depending on where they fall on the spectrum. A child who doesn’t cry or grimace after an injury isn’t necessarily feeling less. They may be processing the sensation differently, or they may lack the typical facial expressions and vocalizations that signal pain to others.
The Case for Heightened Pain Sensitivity
While the stereotype leans toward autistic people feeling less pain, a growing body of research points in the opposite direction. Some autism-associated genes are active in the sensory neurons that carry pain signals from the body to the brain. These neurons are part of the ascending sensory pathway, a relay system that moves pain information through the spinal cord, up to the brain’s processing centers. Genetic differences in this pathway could make pain signals stronger, not weaker.
A core theory in autism neuroscience centers on an imbalance between excitatory and inhibitory brain activity. When excitatory signals dominate, the brain becomes hyper-responsive to incoming information. Researchers have proposed that this same imbalance could drive pain hypersensitivity, meaning the autistic nervous system may amplify pain signals rather than dampen them. One clinical study at a French research hospital was designed specifically to test whether autistic adults show a “pro-nociceptive profile,” essentially a nervous system primed to feel more pain, not less.
When researchers use standardized tools like quantitative sensory testing, which measures exact thresholds for detecting heat, cold, pressure, and pain using calibrated instruments, the results are mixed but often lean toward hypersensitivity. One study of children and adolescents with autism found that participants reported heightened sensitivity to both everyday stimuli and experimental pain, along with reduced ability to suppress sustained painful input. Their brains, measured via EEG during heat stimulation, processed painful stimuli differently at a neurological level.
Why the Confusion Exists
If many autistic people are actually more sensitive to pain, why does the opposite impression persist? Several factors contribute.
- Atypical expression: Autistic people may not show pain through the expected channels like facial grimacing, crying, or verbal complaints. A delayed reaction, a flat expression, or self-soothing behavior like rocking can mask genuine distress.
- Communication differences: Some autistic individuals, particularly those with limited verbal communication, may struggle to identify, label, or report pain. This doesn’t mean the sensation is absent.
- Alexithymia: Many autistic people have difficulty recognizing and describing their own internal states, including pain. They may not consciously register a sensation as “pain” even when their body is responding to it.
- Attention and focus: Intense focus on a task or special interest can temporarily override pain awareness. This is true for anyone, but the depth of focus common in autism may make it more pronounced.
- Observer bias: When caregivers or clinicians expect autistic people to show pain differently, they may underestimate it. The mismatch between expected and actual pain behavior gets interpreted as tolerance rather than different expression.
What This Means in Practice
If you’re an autistic adult who has always shrugged off injuries or noticed pain long after the fact, this pattern fits within the recognized sensory profile of autism. It’s worth paying attention to, because reduced pain awareness can delay treatment for injuries, infections, or medical conditions that would otherwise prompt a doctor visit. Some autistic people have reported discovering broken bones hours or even days after the injury, or missing early signs of appendicitis or dental problems.
For parents noticing this pattern in a child, it’s one piece of a larger puzzle. High pain tolerance alone doesn’t point to autism, but combined with other sensory differences, social communication patterns, or repetitive behaviors, it may warrant a developmental evaluation. Keep in mind that the reverse is equally valid: a child who is extremely sensitive to pain, who screams at minor scrapes or can’t tolerate band-aids, is also showing a sensory pattern consistent with autism.
The most accurate way to think about it is that autism changes how the brain processes pain, and that change can go in either direction. What looks like toughness from the outside may be a neurological difference in how sensory signals are filtered, prioritized, and expressed.