Sensory processing disorder (SPD) is a condition in which the brain has trouble receiving, organizing, and responding to information from the senses. An estimated 5% to 13% of children ages 4 to 6 are affected. Rather than a problem with the senses themselves, SPD is a neurological issue: sensory signals reach the brain but get misinterpreted, amplified, or barely registered at all. The result is reactions to everyday experiences that seem out of proportion, whether that means a child screaming at the feel of a clothing tag or an adult becoming overwhelmed by fluorescent office lighting.
How SPD Works in the Brain
Your sensory receptors work fine. The breakdown happens further along the chain, in the higher-order brain processes responsible for interpreting and prioritizing sensory input. Think of it like a mail sorting facility where letters arrive on time but get routed to the wrong departments. A sound that should register as background noise gets flagged as urgent, or a pain signal that should grab your attention barely registers.
This processing happens across eight sensory systems, not just the five most people know. Beyond sight, hearing, touch, taste, and smell, three additional senses play a major role in SPD. Proprioception detects body position and movement through joints and muscles, which is why some people with SPD seem clumsy or crash into furniture. The vestibular system governs balance, movement, and spatial orientation. Interoception picks up internal signals like hunger, thirst, pain, and emotions. A child who never seems to notice they’re hungry or one who melts down at the faintest stomachache may be processing interoceptive input differently.
The Three Main Types
SPD isn’t one-size-fits-all. Researchers have identified three broad categories, and a person can experience more than one.
Sensory modulation disorder is the most widely recognized type. This is the category that produces the “sensory seekers” and “sensory avoiders” people often read about. Someone who is over-responsive to sensory input may find swinging or spinning frightening, flinch at light touch, or become distressed by sounds others barely notice. Someone who is under-responsive may seem oblivious to pain, seek out intense physical experiences like roughhousing and crashing into cushions, or crave constant movement through bouncing, jumping, and rocking.
Sensory discrimination disorder makes it hard to distinguish between similar sensory inputs. A child with this type might struggle to tell the difference between similar-sounding words, have difficulty locating an object by touch alone, or not notice that their shirt is on backward.
Sensory-based motor disorder affects how the body uses sensory information to plan and execute movement. This can show up as poor posture, difficulty with coordination, trouble learning new physical tasks, or a tendency to bump into things.
What SPD Looks Like Day to Day
In children, SPD often becomes obvious during activities that other kids handle easily. An over-responsive child may refuse certain foods based on texture, cover their ears in a school cafeteria, or have intense emotional reactions to getting dressed. These aren’t tantrums rooted in defiance. The sensory experience is genuinely overwhelming.
Under-responsive children present differently. They may seem zoned out, not respond when their name is called, or need much more sensory input than their peers to feel engaged. Kids who are under-responsive to proprioceptive input often seek out physical touch and enjoy crashing into couches, beds, or anything soft. Children who are acutely sensitive to interoceptive signals may have a noticeably lower pain tolerance or be described as “deep feeling” kids who react strongly to any internal sensation outside their norm.
Many children show a mix, being over-responsive in some senses and under-responsive in others. A child might crave intense vestibular input like spinning but be unable to tolerate the texture of sand.
SPD in Adults
SPD doesn’t disappear with age, though many adults develop coping strategies without realizing they have it. In the workplace, sensory processing difficulties can show up as distractibility in open-plan offices, overreaction when colleagues get too close, or a habit of humming or fidgeting to self-regulate. Some adults miss auditory cues like ringing phones. Others find certain lighting physically draining. Research on working adults found that higher sensory sensitivity was associated with greater perceived stress and burnout symptoms, suggesting that the daily effort of managing sensory input in a world not designed for it takes a real toll on energy and well-being.
Overlap With Autism and ADHD
Sensory differences are extremely common in autism and ADHD, which is one reason SPD can be hard to identify as a standalone condition. Between 50% and 70% of people with autism also have ADHD, and sensory processing difficulties are a feature of both conditions. But SPD also occurs in children and adults who don’t meet criteria for autism or ADHD. This overlap has fueled an ongoing debate about whether SPD is its own distinct condition or a feature of other neurodevelopmental differences.
Why SPD Isn’t an Official Diagnosis
SPD is not currently listed as a formal diagnosis in the DSM-5 (the standard manual for psychiatric conditions) or the ICD-11 (the international classification system). This doesn’t mean the symptoms aren’t real. It means there’s no universally agreed-upon set of diagnostic criteria, which makes it harder to get insurance coverage for treatment and contributes to underdiagnosis. Many clinicians, particularly occupational therapists, recognize and treat SPD in practice even without a formal diagnostic code.
Assessment typically involves standardized questionnaires filled out by parents or teachers, along with clinical observation. The Sensory Profile 2 is one of the most widely recommended tools. It asks caregivers to rate how often a child responds to various sensory experiences in daily life, producing a profile that shows which sensory systems are affected and whether the child tends toward over-responsivity, under-responsivity, or both. Other tools include the Sensory Processing Measure, the Sensory Experience Questionnaire, and hands-on clinical tests for things like balance and body awareness.
How SPD Is Treated
The primary treatment for SPD is occupational therapy, often using an approach called sensory integration therapy. Developed in the 1970s, this method gradually exposes a person to the types of sensory input that are challenging for them, in a controlled, playful environment. The goal is to help the brain learn to process those signals more effectively over time rather than simply avoiding triggers.
Alongside therapy sessions, many occupational therapists create what’s called a sensory diet: a personalized plan of physical activities and accommodations built into a child’s daily routine. The goal is to keep the nervous system in a “just right” state throughout the day. For a child who tends to feel sluggish, a sensory diet might include 20 jumping jacks, bouncing on a therapy ball, or holding a yoga pose before sitting down for schoolwork. For a child who gets easily overstimulated, it might involve calming activities that bring them down from an overloaded state. Sensory diets also include smaller adjustments throughout the day, like using fidget tools, chewing crunchy foods, or doing heavy-work chores like vacuuming and carrying groceries.
Regular use of a sensory diet helps children (and adults) build self-awareness about their own sensory needs. Over time, many people learn to recognize when they’re becoming dysregulated and can choose an activity that helps, whether that’s a quick walk, a few minutes of deep pressure, or stepping into a quieter space. The combination of formal therapy and daily sensory strategies gives most people with SPD meaningful improvement in their ability to participate in school, work, and social life.