impairment, disability, and handicap (ICIDH)
/ ICIDH, say it as the letters eye-see-eye-dee-aitch /
Before the modern ICF, the World Health Organization made an earlier attempt, in 1980, to put disability into a shared language. It was called the International Classification of Impairments, Disabilities and Handicaps, mercifully shortened to ICIDH. Understanding it is worth the trouble, because it shows both the first good idea, that disability has layers, and the flaw that the field later worked hard to correct.
The ICIDH proposed a chain of three terms running outward from the body. Impairment was a loss or abnormality of body structure or function, for example a paralyzed leg. Disability was the resulting restriction in performing an activity in the normal manner, for example being unable to walk. Handicap was the social disadvantage that followed, for example being unable to keep a job or take part in community life. The model captured something real, that a problem in the body ripples out into doing and then into living, and that these are not the same thing.
The ICIDH was retired and replaced by the ICF in 2001 for two main reasons, and this is the part worth remembering. First, its language carried a sting: handicap and to a lesser extent disability had become stigmatizing words that defined people by what they lacked. Second, and more deeply, the model was one-directional, a straight downhill arrow from a broken body to a disadvantaged life, as if disadvantage flowed only from the person. The ICF replaced this with neutral terms (activity limitation, participation restriction) and, crucially, added the environment as an active player, recognizing that society and surroundings, not just the body, create disability. So the ICIDH matters mostly as the model we learned from and moved beyond.
In ICIDH terms a polio survivor had an impairment (a weak leg), a disability (could not walk unaided), and a handicap (could not reach a job up an unramped staircase). The ICF reframes the last one as an environmental barrier, not a label on the person.
ICIDH first split the layers; ICF kept the layers but removed the blame and added the world.
Avoid the word handicap in current practice; it is now considered outdated and stigmatizing. The ICIDH is taught mainly to explain why the modern ICF replaced it.