Why a Diagnosis Does Not Tell the Whole Story
Having a disability is not a single, uniform experience. It exists across a wide spectrum of how people move, think, function, and interact with the world. Categories of disability are too often based solely on medical diagnoses, but they are more accurately understood through function, or how a person is able to navigate daily life. This article explores eight function-based categories of physical disability that better reflect how individuals interact with the world around them.
Core Categories of Disability (Function-Based)
1. Mobility Disabilities
People who have difficulty walking, standing, or moving.
• Full-time wheelchair users (non-ambulatory)
• Ambulatory wheelchair users (can walk short distances but use a chair for endurance, pain, or safety)
• Cane, walker, or brace users
• People with limited stamina or balance issues
Mobility is not all-or-nothing. Many people move between levels depending on the day.
2. Dynamic (Fluctuating) Disabilities
This is one of the most misunderstood categories.
These are conditions that:
• Change day to day (or hour to hour)
• Can appear “fine” one moment and disabling the next
Examples (without focusing on diagnosis):
• Fatigue that suddenly limits function
• Pain that varies in intensity
• Neurological symptoms that come and go
Function is not consistent, and ability is not predictable. This is where the idea of “you don’t look sick” can be challenged.
3. Invisible Disabilities
Disabilities that are not immediately apparent to others.
This includes:
• Chronic pain
• Cognitive impairments (brain fog)
• Sensory sensitivities
• Internal medical conditions
Visibility is not a measure of legitimacy. This category overlaps with many others, which is worth noting.
4. Sensory Disabilities
These affect how a person receives and processes sensory input.
• Vision impairments (partial to total blindness)
• Hearing impairments (hard of hearing to deaf)
• Sensory processing differences (over- or under-sensitivity)
The world is built for certain sensory norms, and deviations from those norms create barriers.
5. Cognitive and Neurological Disabilities
These affect thinking, memory, processing, or executive function.
• Difficulty concentrating or organizing tasks
• Memory gaps
• Slower processing speed
• Overwhelm in complex environments
Intelligence is not the same as cognitive accessibility.
6. Psychiatric and Emotional Disabilities
These impact mood, regulation, perception, and interaction.
• Conditions that affect emotional regulation
• Anxiety, mood instability, or trauma responses that affect daily living
• Social functioning challenges
These are real disabilities, not character flaws, and they have a physiological basis for occurring.
7. Chronic Illness as Disability
These are:
• Ongoing medical conditions that impact daily functioning
• Fatigue, pain, and treatment burden
• Unpredictable health cycles
Disability is often about energy limitation, not just physical limitations.
8. Temporary, Permanent, and Episodic Disabilities
Disabilities can be temporary, permanent, or episodic.
• Temporary (injury, surgery recovery)
• Permanent (expected to last for the duration of life)
• Episodic (comes and goes over time)
Many people will experience disability at some point in their lives. Laws such as the ADA and FMLA serve all three types of disabilities.
Overlapping Categories
A person may belong to multiple categories at once. These categories are not boxes, but lenses. Some people fit into just one category, but most people with disabilities fit into more than one. For example, someone may be an ambulatory wheelchair user with an invisible, dynamic disability and cognitive fatigue.
Examples That Challenge Diagnosis-Based Thinking
Take spina bifida as one example. It is often spoken of as though it represents a single, uniform experience, but the reality is far more varied. Some individuals with spina bifida have balance and mobility challenges but are able to walk independently. Others may walk with the support of canes, crutches, or a rollator. Still others rely on a wheelchair for mobility, either part-time or full-time.
Even within those groups, the experience can change depending on the day, the environment, and the physical demands placed on the body. A person who is able to walk short distances at home may require a wheelchair in larger spaces, not because they cannot walk at all, but because walking comes at a significant physical cost.
This same variability can be seen in multiple sclerosis. Some individuals experience long periods of stability with only mild symptoms, while others live with significant fatigue, mobility challenges, or cognitive changes that affect daily functioning. Symptoms may come and go, sometimes unpredictably, meaning that a person’s level of ability can shift not only over years, but from one day to the next. A person who appears fully capable in one moment may need substantial support in another.
Cerebral palsy offers another perspective. It is a lifelong condition, but the level of impact varies widely from person to person. Some individuals walk independently with minimal visible differences. Others use braces, walkers, or wheelchairs, and may also experience differences in coordination, speech, or muscle control. The condition itself does not change over time in the same way as multiple sclerosis, but the lived experience still differs greatly depending on the individual and their environment.
Autoimmune disease offers another powerful example of how disability cannot be defined by diagnosis alone. Although these conditions are often grouped together medically, the lived experience can vary widely, not only from one person to another, but within the same person over time.
Some individuals live with primarily invisible symptoms such as fatigue, joint pain, or internal inflammation. They may appear outwardly well while managing significant physical limitations beneath the surface. Others experience more visible effects, including mobility challenges that require the use of canes, braces, or wheelchairs, either occasionally or on a regular basis.
Many autoimmune conditions are also dynamic. Symptoms can fluctuate from day to day, with periods of relative stability followed by flares that significantly limit function. A person may be able to complete daily tasks one week and struggle with the same tasks the next. This unpredictability often shapes how they plan their lives, conserve energy, and interact with the world around them.
In some cases, autoimmune disease also affects cognitive function. Individuals may experience difficulty with memory, concentration, or processing information, particularly during periods of increased disease activity. These challenges are not always visible, but they can have a meaningful impact on daily life.
Taken together, autoimmune disease can involve invisible disability, mobility limitations, dynamic or fluctuating function, and cognitive challenges. The diagnosis itself does not determine the experience. The way the condition manifests, and how the individual navigates a world that is not always designed for that variability, is what defines disability in practice.
These examples illustrate a simple but often overlooked truth. The diagnosis may be the same, but the way a person experiences the world, and the way the world responds to them, can be entirely different.
Assistive Devices by Function
Mobility and Movement Support
Devices that help a person move safely, conserve energy, or reduce pain.
• Wheelchairs (manual, power, transport chairs)
• Mobility scooters
• Canes (standard, quad canes)
• Crutches (underarm, forearm)
• Walkers and rollators
• Gait trainers
• Knee scooters
• Transfer boards
• Stair lifts and platform lifts
These devices are not just about the inability to walk. They are often about endurance, safety, and energy conservation.
Positioning, Stability, and Physical Support
Devices that support joints, improve alignment, or prevent injury.
• Braces (knee, ankle-foot orthotics, wrist, back)
• Splints
• Orthotics (custom shoe inserts)
• Postural supports (seating systems, cushions)
• Compression garments (socks, sleeves, gloves)
• Abdominal binders
These are often used by people who may look fully mobile but still need support to function.
Daily Living and Self-Care Aids (ADLs)
Devices that help with everyday tasks like dressing, bathing, and hygiene.
• Sock aids
• Long-handled shoehorns
• Dressing sticks
• Button hooks and zipper pulls
• Reachers and grabbers
• Long-handled sponges
• Shower chairs and bath benches
• Raised toilet seats and grab bars
• Hoyer lifts
• Adaptive clothing
These tools support independence and dignity in very private, everyday activities.
Fine Motor and Hand Function Supports
Devices that help with grip, coordination, or hand strength.
• Built-up utensil handles
• Adaptive pens and pencils
• Jar openers
• Key turners
• Touchscreen styluses
• Writing supports and grips
• Breath-controlled wheelchair systems
• Eye-controlled communication devices
These are especially important for people with arthritis, neuropathy, tremors, or paralysis.
Cognitive and Executive Function Supports
Often overlooked, but incredibly important.
• Medication organizers and timed pill dispensers
• Reminder apps and alarms
• Visual schedules and planners
• Noise-canceling headphones
• Task management tools
Not all assistive devices are physical. Many support thinking, memory, and focus.
Communication Supports
For individuals who have difficulty speaking or processing language.
• Augmentative and Alternative Communication (AAC) devices
• Speech-generating devices
• Communication boards
• Text-to-speech apps
• Eye-controlled computer interfaces
These tools allow people to fully participate in conversations and decision-making.
Sensory Supports
Devices that help regulate sensory input.
• Noise-reducing headphones or earplugs
• Tinted glasses or light filters
• Weighted blankets or lap pads
• Fidget tools
These can make environments tolerable or accessible.
Environmental and Home Modifications
Changes to surroundings that function as assistive supports.
• Ramps
• Widened doorways
• Lever-style door handles
• Smart home devices (voice-controlled lights, locks)
• Adjustable beds
• Lifting devices
• Home elevators or stair lifts
• Lift chairs
Sometimes the device is not something a person wears or carries, but something built into their environment.
Medical Supports That Shape Daily Life
Some assistive supports are medical in nature but still shape how a person moves through the world. Oxygen therapy, for example, allows individuals with respiratory conditions to maintain adequate oxygen levels, but it also affects mobility, endurance, and daily routines. A person may be able to walk short distances without support but require portable oxygen for longer activities, illustrating again how disability is defined not just by diagnosis, but by interaction with the environment.
Accessibility and the Role of the Environment
Assistive devices are not symbols of limitation. They are tools of access. Each one reflects a specific way a person interacts with the world, adapts to it, and claims independence within it.
When a person cannot climb stairs, whether due to using a wheelchair or because of limited balance and mobility, and they are unable to enter a building that has only stairs, it is not the wheelchair or the person’s body that prevents participation. It is the lack of accessibility. The barrier is not the disability. The barrier is the environment.
With access, participation becomes possible. Without it, exclusion is the outcome.
Conclusion
Disability is often treated as something that can be neatly defined by a diagnosis, but as we have seen, the reality is far more complex. The same condition can result in very different experiences depending on how it affects movement, energy, cognition, and daily function. When we begin to understand disability in terms of a variety of experiences rather than just labels, our perspective shifts.
Behind every category, every device, and every label is a person navigating daily life in ways that are often unseen by others. Some adaptations are visible, while others are not. Some needs are constant, while others change without warning. None of these differences make a person less capable of living a full and meaningful life.
When barriers exist, they limit participation. When access is built in, those same individuals can engage, contribute, and thrive. When we understand disability in terms of lived experiences, we move from judgment to awareness, and from awareness to meaningful inclusion.
Accessibility Is Not a Privilege – Jan Mariet’s A Day in the Life
I Couldn’t Even Get in the Door – Jan Mariet’s A Day in the Life
Why Disabled People Are Still Shut Out of Leadership – Jan Mariet’s A Day in the Life