A disability is an impairment that may be cognitive, developmental, intellectual, mental, physical, sensory, or some combination of these. It substantially affects a person's life activities and may be present from birth or occur during a person's lifetime.[1]

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[2]

Disability is a contested concept, with different meanings in different communities.[3] It may be used to refer to physical or mental attributes that some institutions, particularly medicine, view as needing to be fixed (the medical model). It may refer to limitations imposed on people by the constraints of an ableist society (the social model). Or the term may serve to refer to the identity of disabled people. Physiological functional capacity (PFC) is a related term that describes an individual's performance level. It gauges one's ability to perform the physical tasks of daily life and the ease with which these tasks are performed. PFC declines with advancing age to result in frailty, cognitive disorders or physical disorders, all of which may lead to labeling individuals as disabled.[1][4]

The discussion over disability's definition arose out of disability activism in the United States and the United Kingdom in the 1970s, which challenged how the medical concept of disability dominated perception and discourse about disabilities. Debates about proper terminology and their implied politics continue in disability communities and the academic field of disability studies. In some countries, the law requires that disabilities are documented by a healthcare provider in order to assess qualifications for disability benefits.[citation needed]


Contemporary understandings of disability derive from concepts that arose during the West's scientific Enlightenment; prior to the Enlightenment, physical differences were viewed through a different lens.

During the Middle Ages, madness and other conditions were thought to be caused by demons. They were also thought to be part of the natural order, especially during and in the fallout of the Plague, which wrought impairments throughout the general population.[5] In the early modern period there was a shift to seeking biological causes for physical and mental differences, as well as heightened interest in demarcating categories: for example, Ambroise Pare, in the sixteenth century, wrote of "monsters", "prodigies", and "the maimed".[6] The European Enlightenment's emphases on knowledge derived from reason and on the value of natural science to human progress helped spawn the birth of institutions and associated knowledge systems that observed and categorized human beings; among these, the ones significant to the development of today's concepts of disability were asylums, clinics, and, prisons.[5]

Contemporary concepts of disability are rooted in eighteenth- and nineteenth-century developments. Foremost among these was the development of clinical medical discourse, which made the human body visible as a thing to be manipulated, studied, and transformed. These worked in tandem with scientific discourses that sought to classify and categorize and, in so doing, became methods of normalization.[7]

The concept of the "norm" developed in this time period, and is signaled in the work of the Belgian statistician, sociologist, mathematician, and astronomer Adolphe Quetelet, who wrote in the 1830s of l'homme moyen – the average man. Quetelet postulated that one could take the sum of all people's attributes in a given population (such as their height or weight) and find their average, and that this figure should serve as a norm toward which all should aspire.

This idea of a statistical norm threads through the rapid take up of statistics gathering by Britain, United States, and the Western European states during this time period, and it is tied to the rise of eugenics. Disability, as well as other concepts including: abnormal, non-normal, and normalcy came from this.[8] The circulation of these concepts is evident in the popularity of the freak show, where showmen profited from exhibiting people who deviated from those norms.[9]

With the rise of eugenics in the latter part of the nineteenth century, such deviations were viewed as dangerous to the health of entire populations. With disability viewed as part of a person's biological make-up and thus their genetic inheritance, scientists turned their attention to notions of weeding such "deviations" out of the gene pool. Various metrics for assessing a person's genetic fitness, which were then used to deport, sterilize, or institutionalize those deemed unfit. At the end of the Second World War, with the example of Nazi eugenics, eugenics faded from public discourse, and increasingly disability cohered into a set of attributes that medicine could attend to – whether through augmentation, rehabilitation, or treatment. In both contemporary and modern history, disability was often viewed as a by-product of incest between first-degree relatives or second-degree relatives.[10]

In the early 1970s, disability activists began to challenge how society treated disabled people and the medical approach to disability. Due to this work, physical barriers to access were identified. These conditions functionally disabled them, and what is now known as the social model of disability emerged. Coined by Mike Oliver in 1983, this phrase distinguishes between the medical model of disability – under which an impairment needs to be fixed – and the social model of disability – under which the society that limits a person needs to be fixed.[11]

Other Languages
Afrikaans: Gestremdheid
Alemannisch: Behinderung
Ænglisc: Unmeaht
العربية: إعاقة
aragonés: Discapacitat
অসমীয়া: অক্ষমতা
asturianu: Discapacidá
azərbaycanca: Əlillik
Bân-lâm-gú: Phoà-siùⁿ
башҡортса: Зәғифлек
беларуская: Інваліднасць
беларуская (тарашкевіца)‎: Інваліднасьць
български: Инвалидност
bosanski: Invalidnost
brezhoneg: Ampech
català: Discapacitat
čeština: Invalidita
Cymraeg: Anabledd
dansk: Handicap
Deutsch: Behinderung
eesti: Puue
Ελληνικά: Αναπηρία
español: Discapacidad
Esperanto: Malkapablo
euskara: Desgaitasun
فارسی: معلول
français: Handicap
한국어: 장애인
hrvatski: Invalidnost
Bahasa Indonesia: Difabel
íslenska: Fötlun
italiano: Disabilità
עברית: לקות
қазақша: Мүгедектік
Kiswahili: Ulemavu
Кыргызча: Майыптык
Latina: Debilitas
latviešu: Invaliditāte
lietuvių: Negalia
Limburgs: Handicap
македонски: Попреченост
മലയാളം: ഭിന്നശേഷി
Bahasa Melayu: Kehilangan upaya
Mìng-dĕ̤ng-ngṳ̄: Pó̤-sióng
Nederlands: Handicap (medisch)
日本語: 障害者
norsk nynorsk: Funksjonshemming
occitan: Andicap
oʻzbekcha/ўзбекча: Nogironlik
ਪੰਜਾਬੀ: ਅਪਾਹਜਪੁਣਾ
پنجابی: معذوری
Patois: Disabiliti
português: Deficiência
română: Dizabilitate
русский: Инвалидность
sicilianu: Andicappi
Simple English: Disability
slovenščina: Invalidnost
Soomaaliga: Naafo
کوردی: کەمتوانی
српски / srpski: Инвалидност
srpskohrvatski / српскохрватски: Invalidnost
suomi: Vammaisuus
Tagalog: Kapansanan
తెలుగు: వికలాంగులు
Türkçe: Engellilik
Türkmençe: Inwalidlik
українська: Інвалідність
اردو: معذوری
Tiếng Việt: Người khuyết tật
吴语: 残疾人
粵語: 殘廢
中文: 身心障礙