Sensory Processing Disorder (SPD): The Ultimate Guide to Symptoms, Diagnosis, and Treatment

Humans have eight unique sensory processing systems, and SPD may impact any combination. Understanding these systems is key for diagnosis and treatment.
(See infographic below.)

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Q: What are the 8 sensory systems affected by SPD?
A: The eight sensory systems are visual, auditory, tactile, olfactory, gustatory, vestibular, proprioceptive, and interoceptive. SPD can cause over-responsiveness, under-responsiveness, or sensory craving behaviors in any of these systems.

1. The Visual System (Sight)

The visual system is responsible for processing information about light, color, movement, and spatial relationships—essentially, how we interpret what we see. In individuals with SPD, this system may be either over-responsive, under-responsive, or marked by a craving for intense visual input. Difficulties with visual processing can significantly impact learning, attention, daily routines, and the ability to function comfortably in busy or unfamiliar environments.

Over-responsivity (Hypersensitivity):

• Bright lights or glare can cause discomfort or headaches; fluorescent lights may be intolerable.
• Difficulty maintaining eye contact, preferring to look away from people or avoid visual engagement.
• Overwhelmed in visually “busy” rooms with lots of posters, clutter, or colorful decorations; may avoid such environments.
• Frequent squinting, shielding of eyes, or requesting dimmer lighting.
• Difficulty copying information from a board, reading crowded text, or keeping place when tracking words on a page.

Under-responsivity (Hyposensitivity):

• Appears not to notice visual stimuli that others do, such as approaching people or objects.
• Misses visual cues and gestures, leading to missed social or safety information.
• Difficulty finding objects in a cluttered space (“visual figure ground” issues).
• May seem “spacey” or disconnected in visually demanding environments.

Sensory Craving (Seeking):

• Fascination with spinning objects, flashing lights, or contrasting colors (e.g., staring at ceiling fans, flipping light switches repeatedly).
• Frequently drawn to screens with rapidly changing images, video games, or animated graphics.
• May align or arrange objects for visual satisfaction (lining up toys, sorting items by color).

Everyday Impacts:

• Challenges with transitions and focus in classrooms or workplaces with heavy visual stimulation.
• Discomfort or distraction in malls, grocery stores, or social gatherings due to visual overload.
• Visual processing issues can co-occur with tasks such as reading, handwriting, or navigating through space, contributing to academic and functional setbacks without targeted accommodations.

Support Strategies:

• Use natural lighting when possible and provide options for desk lamps or sunglasses indoors.
• Minimize classroom or workplace visual clutter; organize materials in clear, labeled bins.
• Use overlays or line guides to help with reading and tracking text.
• Provide advance warning and support for transitions in visually busy environments.
• Consider vision therapy or visual perceptual exercises as part of an occupational therapy plan.

By identifying and appropriately supporting visual processing challenges, individuals with SPD can dramatically reduce day-to-day visual fatigue, anxiety, and overwhelm—improving comfort, participation, and learning outcomes.

2. The Auditory System (Sound)

The auditory system is responsible for processing all the sounds we hear—volume, pitch, frequency, and rhythm. For individuals with SPD, auditory processing differences can lead to both practical and emotional challenges at every life stage, from noisy classrooms to bustling workplaces or even the comfort of home.

Over-responsivity (Hypersensitivity):

• Everyday environmental noises (vacuums, toilets flushing, sirens, loud voices) may feel painfully loud or startling.
• May cover their ears, cry, or flee from busy places like cafeterias, malls, or parties.
• Struggles with group settings due to background noise (“auditory figure ground” issues); unable to filter out irrelevant sounds.
• Easily distracted or distressed by humming lights, appliances, or people talking nearby.
• Nervous system may go into “fight or flight” from loud or unexpected sounds, leading to sudden meltdowns or shutdowns.

Under-responsivity (Hyposensitivity):

• May not notice when someone calls their name or when a bell rings in school.
• Fails to respond to important environmental cues (alarms, car horns).
• Talks at a higher volume and may prefer environments others find too loud.
• May enjoy making repetitive or loud noises or seek out environments with rich auditory input.

Sensory Craving (Seeking):

• Frequently seeks out loud environments, music, or sound-producing toys.
• Repeatedly bangs objects together or hums, sings, or talks to themselves for auditory stimulation.
• May focus better with background sound (white noise, music) and become restless or inattentive in quiet spaces.

Everyday Impacts:

• Difficulty following verbal instructions, especially in noisy settings.
• Fatigue or headaches from auditory overload.
• Social challenges, such as missing key parts of conversations or becoming overwhelmed in group activities.
• At risk for being misunderstood as inattentive, disruptive, or even hearing-impaired.

Support Strategies:

• Provide noise-canceling headphones or earplugs in loud environments.
• Use visual instructions or written checklists to reinforce verbal communication.
• Allow for “quiet zones” or auditory breaks throughout the day.
• Minimize background noise in classrooms and workplaces whenever possible (close doors, turn off unused electronics).
• Teach use of self-advocacy scripts: asking for repetition, clarification, or a quieter space when needed.
• In some cases, work with an audiologist or auditory integration therapist as part of a sensory-focused intervention plan.

By understanding and supporting auditory processing differences, you can reduce anxiety and stress, making it easier to function in and enjoy a wide variety of environments.

3. The Tactile System (Touch)

The tactile system governs how the body experiences touch, including pressure, temperature, pain, and texture. It plays a critical role in everything from fine motor skills and self-care routines to social bonding and environmental awareness. Disruptions in tactile processing are among the most recognized features of SPD and can dramatically affect daily comfort and participation in activities.

Over-responsivity (Hypersensitivity):

• Finds certain clothing textures (tags, seams, socks) unbearable, often refusing to wear them or insisting on changes multiple times a day.
• Avoids messy play (finger paint, sand, mud), food with mixed textures, or hands-on group activities.
• Flinches, startles, or recoils from light touches, pats, or hugs—even from loved ones.
• Strong reactions (crying, tantrums, withdrawal) to routine hygiene like haircuts, nail trimming, tooth brushing, or bathing.
• May refuse to walk barefoot on grass, sand, or other uneven surfaces.

Under-responsivity (Hyposensitivity):

• Rarely notices when face, hands, or clothes are dirty, or when shoes are on the wrong feet.
• High pain tolerance—may not cry or react to scrapes, cuts, or bumps that would usually warrant attention.
• Frequently touches objects and people without apparent need; seeks tactile feedback for reassurance or stimulation.
• Doesn’t respond to hot/cold temperatures appropriately or fails to notice minor injuries.

Sensory Craving (Seeking):

• Seeks out firm hugs, roughhousing, wrestling, or direct physical input from others (“crash and bump” play).
• Enjoys fidgeting with textured objects, frequent hand-washing, or running hands along walls and furniture.
• May chew or mouth non-food objects such as shirt collars, pencils, or toys for tactile input.

Everyday Impacts:

• School: Struggles with classroom tasks like cutting with scissors, gluing, or using certain writing tools; may melt down during art or sensory activities.
• Social: May be labeled “overly dramatic,” “fussy,” “clumsy,” or “in their own world” due to avoidance or constant seeking of physical touch.
• Home: Battles with routines like dressing, grooming, or participating in family meals.

Support Strategies:

• Remove tags and select seamless or extra-soft clothing; allow the individual to choose preferred fabrics.
• Gradually introduce new textures through sensory play, using a “just right” challenge (never forced).
• Provide alternatives—weighted blankets, fidget tools, or chewy necklaces—for safe tactile input.
• Use visuals and social stories to prepare for tactile experiences such as haircuts, doctor visits, or group activities.
• For children, collaborate with occupational therapists for a sensory diet and a stepwise desensitization plan (gradual exposure to challenging textures).

Recognizing and validating tactile sensitivities ensures individuals with SPD feel supported, safe, and empowered to participate fully in school, home, and community life. Strategic, respectful accommodations help reduce anxiety, minimize meltdowns, and build confidence for new experiences.

4. The Olfactory System (Smell)

The olfactory system governs our sense of smell and plays a surprisingly important role in comfort, appetite, memory, emotional regulation, and even personal safety. For individuals with SPD, the way they process olfactory information may be dramatically heightened (over-responsive), dulled (under-responsive), or characterized by a constant craving for odor-based sensations.

Over-responsivity (Hypersensitivity):

• Strong, commonly encountered odors (perfume, cleaning supplies, cooked foods, cigarette smoke, body odor) may be overwhelming, nauseating, or even sickening.
• Gagging or vomiting when entering certain environments, such as cafeterias, public restrooms, or stores with strong scents (candles, soaps, fresh produce).
• Refusal to eat due to dislike of the smell of specific foods; can significantly complicate mealtime or social gatherings where unfamiliar foods are present.
• Avoids places, people, or activities associated with problematic smells (art class, lunchroom, certain relatives’ homes).

Under-responsivity (Hyposensitivity):

• May not notice pungent or dangerous smells like spoiled food, gas leaks, smoke, or strong chemical odors, increasing safety risks.
• Frequently fails to realize unpleasant body odors or dirty laundry (can affect social acceptance and self-awareness).
• Seeks out additional olfactory input, requesting more strongly scented products (shampoos, lotions, foods).

Sensory Craving (Seeking):

• Deliberately smells objects, food, people, or animals, sometimes to the confusion or concern of others.
• Enjoys activities with intense olfactory input—cooking aromatic foods, using scented markers, spending time in scented stores.
• May become fixated on or preoccupied with certain smells, such as rubber, gasoline, markers, or other distinctive substances.

Everyday Impacts:

• Can lead to challenges with eating, feeding, and nutrition; highly sensitive children may have restricted diets purely because of smell aversions.
• Olfactory triggers can cause emotional outbursts, meltdowns, or withdrawal in environments that are otherwise typical for peers.
• In adults, workplace participation or social engagement may be impacted if there are unavoidable unpleasant or overwhelming odors (e.g., office kitchen, shared bathrooms).

Support Strategies:

• Avoid strong-smelling cleaning products, perfumes, or air fresheners at home and school; use fragrance-free alternatives.
• Allow individuals to bring a familiar, calming scent (like a scented cloth or essential oil) if new environments are unavoidable.
• Provide advance warning before entering places with distinctive odors, allowing for coping strategies (e.g., using a face mask or taking brief breaks).
• For picky eaters, introduce foods with mild scents first and gradually build tolerance under the guidance of an OT or feeding therapist.
• Educate caregivers, teachers, and peers about olfactory sensitivities to foster empathy and support in group settings.

By acknowledging and proactively supporting olfactory processing needs, individuals with SPD can enjoy greater participation in daily life, minimize distress, and develop effective coping strategies for challenging environments.

5. The Gustatory System (Taste)

The gustatory system manages our perception of taste, including flavors, textures, and temperatures experienced in the mouth. Taste processing challenges are frequently intertwined with feeding, nutrition, oral care, and social participation. When this system doesn’t interpret taste and texture signals accurately, eating and mealtime routines can become battlegrounds for children, a source of anxiety and embarrassment for teens, and a hidden, ongoing stressor for adults.

Over-responsivity (Hypersensitivity):

• Reacts strongly to certain flavors (bitter, sour, spicy) and food temperatures; may gag, spit out, or refuse foods entirely.
• Restricts diet to a very limited menu of “safe” or familiar foods, sometimes leading to nutritional deficiencies or “picky eating.”
• Texture aversions extend to refusal of crunchy foods, chewy meats, creamy substances, or mixed textures (such as casseroles or yogurt with fruit).
• Intense dislike of toothpaste flavors, mouthwash, or certain medications, making oral hygiene challenging.
• May avoid social situations involving food (birthday parties, school lunch, eating out).

Under-responsivity (Hyposensitivity):

• Seeks highly flavored, spicy, or very sour foods to get adequate sensory input.
• Enjoys combining unusual flavor pairings or eating foods others find too bland or too intense.
• Stuffs mouth with too much food at once or chews excessively without swallowing, sometimes resulting in choking hazards.
• Fails to notice food at extreme temperatures or spoiled food, increasing risk of burns or illness.

Sensory Craving (Seeking):

• Chews on non-food objects (shirt collars, pencils, erasers, small toys) for oral stimulation.
• Repeatedly seeks foods with strong flavors, textures, or crunch (ice, hard candies, chewy snacks).
• May attempt to taste or mouth objects that are not intended for consumption, raising both sensory and safety concerns.

Everyday Impacts:

• Restricted diets can compromise growth, development, and family meal participation; some children may need referral to a feeding therapist.
• Oral hygiene battles become sources of family stress; children may resist brushing teeth, allowing cavities and dental problems to develop.
• In teens and adults, avoidance of social meals or embarrassment about food preferences can create social isolation.
• Eating challenges can lead to mealtime power struggles, anxiety, or even disordered eating patterns without proper support.

Support Strategies:

• Introduce new foods and textures gradually, keeping mealtimes low-pressure and avoiding coercion.
• Work with occupational or feeding therapists who use approaches like food chaining and desensitization.
• Offer a variety of temperatures, flavors, and textures in small, manageable amounts.
• Use alternative oral sensory tools (chewelry, safe chew tubes) to meet craving needs in appropriate ways.
• Choose mild, preferred flavors for daily oral care, and allow for routine and choice in hygiene routines.
• Include social stories, visual supports, and preparation for unfamiliar food situations to reduce anxiety.
• Involve children in grocery shopping, preparing, or choosing foods to increase their comfort and buy-in with new tastes and textures.

Validating taste sensitivities and building positive, consistent routines around eating help individuals with SPD enjoy nutritious diets, maintain oral health, and confidently participate in social and family food experiences.

6. The Vestibular System (Balance and Motion)

The vestibular system, located within the inner ear, allows us to detect motion, gravity, and spatial orientation. It is essential for balance, coordination, and knowing where our body is in space. When vestibular processing is disrupted—as is common in SPD—individuals may be either extremely sensitive to movement or crave intense movement sensations.

Over-responsivity (Hypersensitivity):

• Shows extreme fear or resistance when feet leave the ground—climbing stairs, riding in elevators, or playing on swings can cause distress.
• Avoids playground equipment, rides, escalators, or other activities involving movement.
• Experiences dizziness, motion sickness, or imbalance from minor movements (e.g., car rides, spinning, tilting).
• May become disoriented, nauseous, or anxious in busy environments or during quick transitions involving movement.

Under-responsivity (Hyposensitivity):

• Appears unaware of motion cues; may not notice when moving quickly or being jostled.
• Seems clumsy, falling or stumbling often, or bumping into people and objects.
• Displays delayed reaction to changes in position or orientation, such as getting dizzy more slowly (or not at all) after spinning.
• Has trouble with activities requiring balance and postural control, like riding a bike or standing on one foot.

Sensory Craving (Seeking):

• Seeks out intense or continuous movement—spinning, swinging, jumping, rocking, or rolling.
• Enjoys amusement park rides others might find unsettling or overwhelming.
• Often fidgets, rocks in chairs, or performs constant, repetitive motions when seated.
• May have difficulty sitting still and appear “in perpetual motion.”

Everyday Impacts:

• At school: Difficulty participating in PE or on the playground, trouble transitioning between classrooms, or feeling overwhelmed during group activities requiring movement.
• At home: “Rough-and-tumble” play, jumping on furniture, spinning in circles, or constantly seeking movement may become disruptive.
• Teens and adults may avoid activities like driving, exercising, or sports due to persistent dizziness or balance problems, or conversely, may pursue high-intensity movement sports for stimulation.
• Poor vestibular processing can also affect the ability to focus, read, or complete tasks that require stillness and head control.

Support Strategies:

• Gradually introduce movement activities in a safe, supportive environment; use harnesses, handholds, or soft mats as appropriate.
• For those with over-responsivity, gently expand tolerance to movement with slow, predictable rocking, swinging, or low-impact exercise, always respecting comfort limits.
• For craving profiles, incorporate “heavy work” activities (crawling, pushing, carrying) to ground the vestibular system and provide deep input.
• Provide movement breaks throughout the day to help regulate energy and attention.
• Occupational therapists may recommend specific vestibular exercises or therapy equipment (e.g., balance boards, swings) as part of a sensory integration plan.
• Foster self-advocacy: teach individuals to recognize when they need movement or when to ask for a break from motion.

Validating vestibular needs and scaffolding experiences with patience can make daily life less stressful and more successful for individuals with SPD, enabling participation in school, home, and community activities with greater confidence and ease.

7. The Proprioceptive System (Body Awareness)

The proprioceptive system is responsible for providing the brain with information about body position, movement, and the amount of force needed to perform different tasks. These signals come from muscles, joints, and connective tissues, helping us move smoothly, apply the right amount of strength, and coordinate our bodies without constantly looking at our limbs. When proprioception is disrupted, individuals may struggle with everything from buttoning a shirt to playing sports.

Over-responsivity (Hypersensitivity):

• Moves with stiff, guarded motions to avoid bumping or unexpected touch.
• Avoids active play, climbing, or participating in group sports due to discomfort or fear of losing control of body movements.
• May react strongly and negatively to deep pressure or heavy physical contact.

Under-responsivity (Hyposensitivity):

• Appears clumsy, frequently bumps into furniture or people, or drops objects unintentionally.
• Has difficulty judging how much force is needed to perform physical tasks (e.g., may break pencils, grip utensils too tightly, or slam doors unintentionally).
• May not notice when they are applying too much or too little pressure, resulting in poor handwriting, awkward movement patterns, or messy eating.
• Seeks out deep pressure or resistance, like leaning heavily on desks or walls, pulling or pushing objects, or crashing into couches and bean bags.

Sensory Craving (Seeking):

• Craves physical input and often engages in “crash and bump” play—jumping, roughhousing, squeezing through tight spaces, or piling under heavy blankets.
• Enjoys activities that provide deep muscle input: carrying heavy backpacks, pushing shopping carts, climbing, running, or jumping.
• Regularly seeks out tight hugs, wears weighted vests, or longs for heavy compression clothing.

Everyday Impacts:

• At school: May be seen as disruptive or inattentive when actually trying to regulate their own input by standing, stretching, or walking around.
• At home: Needs reminders for gentle contact with others, may accidentally hurt siblings or friends during play, or struggles with fine motor tasks like tying shoes or using silverware.
• In teens and adults: Problems with handwriting, fatigue during manual chores, or discomfort in exercise or sports contexts. They may also seek out gyms or jobs requiring heavy lifting for self-regulatory reasons.

Support Strategies:

• Incorporate “heavy work” activities into daily routines (e.g., pushing/pulling, carrying groceries, animal walks, resistance bands).
• Offer opportunities for proprioceptive input before challenging sensory situations (e.g., jumping jacks before a crowded assembly or workplace presentation).
• Use weighted vests, lap pads, or compression clothing with guidance from an occupational therapist.
• Teach clear boundaries and safe ways to get deep pressure input during play or in social settings.
• For writing, provide adaptive tools like pencil grips and lined paper, and break tasks into manageable steps.
• Collaborate with an OT to create a sensory diet that includes proprioceptive input, customized to individual needs and context.

Understanding and addressing proprioceptive processing challenges can improve body coordination, reduce frustration, and help individuals feel more comfortable and confident as they move through their day. By tailoring environments and routines to include safe, structured sources of deep sensory input, families and educators can empower children and adults with SPD to thrive.

8. The Interoceptive System (Internal Body States)

The interoceptive system manages internal sensations—hunger, thirst, body temperature, need to use the bathroom, pain, fatigue, and emotional states. This “hidden” sense helps us recognize basic needs and maintain physical and emotional balance. In Sensory Processing Disorder, disruptions in interoception can significantly impact everyday life, personal well-being, and even safety.

Over-responsivity (Hypersensitivity):

• Experiences discomfort or anxiety linked to subtle bodily cues, such as mild hunger, a slightly full bladder, or minor aches.
• May feel overwhelmed by internal changes (e.g., elevated heart rate during mild stress or excitement).
• Reacts strongly to sensations that others perceive as minimal, sometimes leading to heightened anxiety or panic during routine bodily changes.

Under-responsivity (Hyposensitivity):

• Rarely notices typical cues for thirst, hunger, or the need to use the bathroom—may skip meals unintentionally or have frequent accidents.
• Can ignore signs of illness, pain, or injury (e.g., not realizing they have a fever, missed meals, dehydration, or cuts and bruises).
• Has trouble recognizing when they’re too hot or cold, leading to poor self-care related to clothing and hydration.

Sensory Craving (Seeking):

• Seeks strong interoceptive input, such as exercising intensely to “feel alive” or eating spicy food for pronounced internal sensations.
• May verbalize vague discomfort, seeking reassurance or intense feelings to recognize their internal state.

Everyday Impacts:

• Challenges with toilet training or bathroom routines in children, sometimes misinterpreted as behavioral issues.
• Difficulty with regulating emotions, such as being slow to recognize or act on feelings of stress, anger, or excitement—can lead to meltdowns or emotional outbursts.
• In teens and adults, trouble pacing meals, staying hydrated, identifying illness, or practicing appropriate self-care (e.g., dressing for weather, resting when sick).
• Emotional self-awareness can be affected, which influences confidence, communication, and peer relationships.

Support Strategies:

• Use visual schedules, timers, or reminders for meals, drinks, and bathroom breaks.
• Teach individuals to check in with their bodies regularly (e.g., “How does my stomach feel? Am I too hot or cold right now?”).
• Work on labeling and expressing emotions through role play, social stories, and charts—linking physical sensations to emotional states.
• Gradually introduce body scanning and mindfulness practices to improve internal awareness in older children and adults.
• Collaborate with occupational therapists for customized interoceptive activities and regulation tools.

Understanding and supporting interoceptive challenges is essential for promoting independent self-care, emotional regulation, and overall well-being throughout life. By making the invisible visible, families and professionals can provide compassionate support tailored to each individual’s unique sensory needs.