Understanding Disability, Impairment, Conditions and Diseases.

Key findings:

Around 15% of the global population – over a billion people – lives with some form of disability, of whom 2–4% experience significant difficulties in functioning. Many of these people require assistive technologies such as low-vision devices, wheelchairs or hearing aids. This number is expected to double to 2 billion by 2050.
Women are more likely to experience disability than men and older people more than young.
Low and middle-income countries have higher rates of disability than high-income countries, and the impact of disability on people in poorer areas is compounded by issues of accessibility and lack of health care services.
Indigenous persons, internally displaced or stateless persons, refugees, migrants and prisoners with a disability also face particular challenges in accessing services.
In recent years, the understanding of disability has moved away from a physical or medical perspective to one that takes into account a person’s physical, social and political context.

Today, disability is understood to arise from the interaction between a person’s health condition or impairment and the multitude of influencing factors in their environment. Great strides have been made to make the world more accessible for people living with disability; however, much more work is required to meet their needs.

Disability is conceptualised as being a multidimensional experience for the person involved. Disabilities can affect people in different ways, even when one person has the same type of disability as another person.

Correspondingly, three dimensions of disability are recognized in The International Classification of Functioning, Disability and Health (ICF) that include:

Body structure and function (and impairment thereof)
Activity (and activity restrictions)
Participation (and participation restrictions)
The role of physical and social environmental factors in affecting disability outcomes.

Disability is a contested concept, with different meanings in different cultures and communities.

The term disability may refer to physical or mental limitations imposed on people by the constraints of an ableist society resulting in activity limitation and participation restrictions. The definition of disability under the Equality Act 2010 is absolute (and protects an individual from discrimination) if you have a physical or mental impairment that has a ‘substantial’ and ‘long-term’ negative effect on your ability to do normal daily activities.

But that does not mean that a person with a disability cannot participate equally. It is important to remember that the word ‘disabled’ is an adjective, not a noun. People are not conditions. It is therefore preferable not to use the term ‘the disabled’; but rather ‘persons with disabilities.’

Disability

A disability is any known condition that makes it more difficult for a person to do certain activities or interact with the world around them. These conditions, or impairments, may be cognitive, developmental, intellectual, mental, physical, sensory, or a combination of multiple factors. Impairments causing disability may be present from birth or occur during a person’s lifetime.

The World Health Organisation proposes the following definition of disabilities:

“Disabilities is an umbrella term, covering impairments, activity limitations, and participation restrictions. An impairment is a problem in body function or structure; an activity limitation is a difficulty encountered by an individual in executing a task or action; while a participation restriction is a problem experienced by an individual in involvement in life situations. Disability is thus not just a health problem. It is a complex phenomenon, reflecting the interaction between features of a person’s body and features of the society in which he or she lives.” (World Health Organization, Disabilities)

Synonyms: disorder, condition, dysfunction, affliction, ailment, complaint, illness, malady

Types of disabilities include:

Physical disabilities

A physical disability is one that affects a person’s mobility or dexterity. A person with a physical disability may need to use some sort of equipment for assistance with mobility. It also includes people who have lost limbs or who, because of the shape of their body, require slight adaptations to be made to enable them to participate fully in society. Examples include: Paraplegia, Quadriplegia, Multiple sclerosis (MS), Hemiplegia, Cerebral palsy Absent limb/reduced limb function, Dystrophy and Polio.

Intellectual or Learning Disabilities

People with intellectual, learning, or cognitive disability have a reduced capacity to learn tasks or process information. A learning disability may make it difficult for a person to take in information and communicate what they know. Learning difficulties can cause difficulties in reading, writing, or mathematics. Learning disabilities and Attention Deficit Disorder together affect between 3% and 10% of the population.

Psychiatric disabilities

A psychiatric disability (or mental illness) can develop at any age and is often not apparent to other people. Psychiatric disabilities are often the most misunderstood disabilities in the community, and peoples’ attitudes may be based on prejudice and myth (e.g. schizophrenics are potentially violent). Mental illnesses can include stress-related conditions, major depression, bipolar disorder (formerly called manic-depressive illness), anxiety, and schizophrenia. Depression is the most common non-psychotic mental illness (psychosis being a disorder which features the loss of contact with reality).

Visual impairments

Only 5% of ‘blind’ people can’t see anything. Visual impairments can be caused by a multitude of factors, including disease, accidents, and congenital illnesses. There is a difference between the needs of visually impaired individuals and blind people.

Hearing impairments

Deafness and hearing loss can be caused by a wide range of factors, including physical damage, disease during pregnancy, or exposure to very loud noises. There is a distinction between people who are deaf and those who have a hearing impairment. Those hearing up to three years of age (when language begins to develop) often have comparatively good speech and lip-reading ability.

Neurological disabilities

Neurological disability is associated with damage to the nervous system that results in the loss of some physical or mental functions. A neurological disability may affect a person’s capacity to move or manipulate things or the way they act or express their feelings. The way they think and process information may also be significantly influenced. The brain and the spine are the areas of the body most closely associated with neurology. Heart attacks, serious infections, and lack of oxygen to the brain may also result in a neurological disability.

Hidden or ‘Invisible’ disabilities

Some disabilities may be hidden, known as an invisible disability. There are many types of disabilities, such as those that affect a person’s Vision, Hearing, Thinking, Learning, Movement, Mental health, Remembering, Communicating and Social relationships. Invisible Disabilities are disabilities that are not immediately apparent to others. It is estimated that 10% of people in the U.S. have a medical condition considered a type of invisible disability.

Impairments

The World Health Organization (WHO) suggested the following definition in Impairment in 1980:

‘A loss or abnormality of a psychological, physiological, or anatomical structure or function. Impairments and disabilities may be temporary or permanent, reversible or irreversible, and progressive or regressive. The functional ability of people who are diagnosed as having the same impairment or disability may vary widely’ (World Health Organisation, Impairment)

The term impairment refers to a person’s actual condition. Impairment is a specific condition with a person’s body. The World Health Organization defines impairment as ‘any loss or abnormality of a psychological, physiological or anatomical structure or function’.

Impairment may refer to any loss or a-typical of a physiological, psychological, or anatomical structure or function, whether permanent or temporary. Identifying impairments that contribute to disability is a key factor for outcomes and further assistance. Examples of impairments include loss of a limb, loss of vision or memory loss, and ‘Activity limitation’ such as difficulty seeing, hearing, walking, or problem-solving.

Knowledge about impairments and disabilities is important to understand possible achieve standardisation of activities for all. It is also a prerequisite for designing and producing products, equipment and services that can be used by as many people as possible, and for developing specialised equipment designed to assist those with a disability, impairment or long-term condition.

Synonyms: disablement, disability, handicap, impairment (noun).

Types of impairments include:

Visual Impairment

In medical terms, visual impairment can be defined as a total loss of, or reduced ability to, perceive light and colour. Within this legal definition, a wide variety of visual impairments can be found with a great dependency on information from other modalities, in particular touch and hearing. The incidence of all kinds of visual impairment increases considerably with age.

Hearing Impairment

Hearing impairment implies a total or partial loss of the ability to perceive acoustic information. The impairment may affect the full range of hearing or be limited to only parts of the auditory spectrum. The onset of the hearing impairment is important for language development and for identification with the deaf community.

Impairment of Speech Production

Speech impairment refers to any reduction in a person’s ability to use speech in a functional and intelligible way. The impairment may influence speech in a general way, or only certain aspects of it, such as fluency or voice volume. Speech impairment may be due to a number of different factors. It may or may not be linked with difficulties in speech perception or comprehension.

Impairment of Language Comprehension

This category contains a loss of, or a reduction in, the ability to understand language. The disability may imply only an impairment of language, or it may be associated with a more general intellectual impairment. Several disorders of the central nervous system may include impairment of language comprehension. Impaired language comprehension may also be developmental or acquired. The understanding of language may be strongly related to context, which means that comprehension is very dependent on non-linguistic cues, such as the presence of persons or objects, or limited to a small number of well known situations.

Intellectual Impairment

People with reduced intellectual ability constitute a very diverse group with a range of sensory, motor and cognitive impairments; most impairments, including visual and auditory impairment, have a higher incidence in the group that is called intellectually impaired. One common trait is that they tend to do work through activities at a slower rate than others, and in some instances have reduced comprehension of instructions and language in general.

Reading Impairment

The Diversity or ‘Universalism’ Model of Disability views disability as ‘human variation’ and ‘universalism’ (to overcome the false dichotomy of ability/disability, Bickenbach et al.,1999); an alternative model intended to focus attention on how society’s systems respond to variation introduced by disability (Scotch and Shriner 1997). Under this model, the diversity of disability must be acknowledged, as well as (all) of the barriers faced by people with disability are (built-environment) imposed and therefore removable; for theory development, research and advocacy it is believed that this model serves disabled persons more effectively than a civil rights or minority group approach (p. 1173) – (Models of Disability and Human Rights: Informing the Improvement of Built Environment Accessibility for People with Disability at Neighborhood Scale?)

Reduced Function of Arms and Hands

Reduced function of arms and hands includes the lack of arms or hands, or reduced ability to use them due to reduced strength or co-ordination. This, in some cases, however, does not influence speech communication itself but implies great difficulty in using a wide range of technical and non-technical equipment. Reduced function of arms and hands due to reduced coordination is usually a result of neurological damage, in some cases. As such, reduced ability to coordinate the movements of the arms and hands will influence all activities that demand manipulation of objects or equipment. Impaired coordination may also increase the probability of hitting and breaking things, and to make errors when operating equipment.

Reduced Function of Legs and Feet

A reduced function of legs and feet implies a dependency on a wheelchair or other mobility aid to help walking (e.g. crutch or stick). People with this disability are more generally otherwise able to communicate with no difficulty.

Impairment of Growth

Impairment of growth primarily includes adults who are significantly shorter than the population mean. This condition is typically caused by malfunctioning of the hormone system. It should be noted, however, that also people who are significantly taller than the average of the population may have some problems in using equipment that is mounted at a low level.

Other Impairments and Disabilities

The above categories cover a wide range of impairments and disabilities. There are, however, individuals who do not readily fit into any of these categories. British studies indicate that at any given time, 0.5 percent of the population are in bed for a limited period, due to disease or accident. This is only one example of a common temporary disability. Similarly, some people have multiple impairments; for example, individuals with intellectual impairments typically have several impairments.

(Medical) Condition

The term ‘medical condition’ generally is a broad term that includes mental illnesses, but nevertheless poses implications for the provision of health care. The term might also be used to indicate grades of health (eg.stable, serious, or critical condition), or to specifically indicate the presence of pathology or illness, In some contexts the term is used specifically to denote any illness, injury, or disease, any physiologic, mental or psychological condition or disorder (e.g., orthopaedic; visual, speech or hearing impairments; and/or specific learning disabilities), excluding mental disorders.

As it is more value-neutral than terms like disease, people sometimes prefer the term ‘medical condition.’ The term medical condition is also a synonym for medical state, which describes an individual patient’s current state from a medical standpoint. Whereby the terming of a disease is used, this defines an a-typical condition that negatively affects the structure or function of all or part of an organism, and that is not due to any immediate external injury. Diseases are often known to be medical conditions that are associated with specific symptoms and signs.

Examples of medical conditions include (but are not limited to)

Alzheimer disease and dementia
Arthritis
Asthma
Cancer
COPD
Crohn disease
Cystic fibrosis
Diabetes

Comparisons

Impairment and Disability

Generally speaking, an impairment is an actual condition, while a disability is the restriction of ability caused by the condition.

Medical Condition and Disease

Generally speaking, a condition simply indicates a state of health; however when related to a temporary or ongoing illness might be further classified as a disease or a disorder. As such, the term condition might be used in place of disease or disorder when a value-neutral term is desired. Disease is often used in a general sense when referring to conditions affecting a physical system or a part of the body. The term also may be used in specific senses but is perhaps most often used when referring to a condition that possesses specific characteristics.

Disease and Disorder

Compared with disease, disorder is less restrictive: disorder involves a disturbance of function but stresses structural change (in negative terms). Because disorder, like condition, is relatively value-neutral when compared with disease, it is often used in place of the latter term when a less stigmatising is desirable.

In short, what distinguishes condition, disease, and disorder from one another would seem to be their relative emphases on functional change, structural change, presence of signs and symptoms, a mode of stigmatisation both socially and culturally.

Notes: ICF – The International Classification of Functioning, Disability and Health, also known as ICF, is a classification of the health components of functioning and disability. This classification was first created in 1980 and then called the International Classification of Impairments, Disabilities, and Handicaps, or ICIDH by WHO to provide a unifying framework for classifying the health components of functioning and disability.

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