Where does impairment collide?

In the World Health Organization's framework for functioning and disability, an impairment is a problem in a body function or structure: a significant loss or deviation such as reduced hearing, limited joint movement, or weakened memory. The WHO's International classification of functioning, disability and health treats impairment as one level of a larger model, distinct from the activity limitations and participation restrictions it may lead to. The referent is a measurable departure from typical body function or anatomy, assessed against clinical norms, and it has nothing to do with writing down an asset's value except for the shared bare meaning of something diminished.[1]

Unit

The degree of loss or deviation in a specified body function or structure

Recovery means

Some impairments are reversible with treatment or rehabilitation; others are stable or progressive

Measured by

Graded against clinical norms for the specific function (e.g., audiometric thresholds, range-of-motion, strength or cognitive scores)

In clinical neurology, mild cognitive impairment names a measurable decline in memory or other thinking skills that is greater than expected for a person's age yet not severe enough to meet the threshold for dementia, often marking a transitional stage toward it. Petersen's 2004 Mild cognitive impairment as a diagnostic entity set out the criteria that distinguish it from both normal aging and dementia. The referent is a clinical category of cognitive decline defined by objective testing with preserved daily function, and it is a different construct from an accounting write-down or a generic body-structure deficit, joined to them only by the word.[2]

Unit

Cognitive performance below age norms with daily function still intact

Recovery means

Some cases revert to normal; many are stable, and a share progress to dementia

Measured by

Established by objective cognitive testing against age- and education-matched norms, with largely preserved activities of daily living