Idiopathic disease

Anidiopathic diseaseis anydiseasewith an unknown cause or mechanism of apparentspontaneousorigin.

For some medical conditions, one or more causes are somewhat understood, but in a certain percentage of people with the condition, the cause may not be readily apparent or characterized. In these cases, the origin of the condition is said to beidiopathic.With some other medical conditions, the root cause for a large percentage of all cases has not been established—for example,focal segmental glomerulosclerosisorankylosing spondylitis;the majority of these cases are deemed idiopathic.Certain medical conditions, when idiopathic, notably some forms ofepilepsyandstroke,are preferentially described by the synonymous term ofcryptogenic.

Derivation

The term 'idiopathic' derives fromGreekἴδιοςidios"one's own" and πάθοςpathos"suffering", soidiopathymeans approximately "a disease of its own kind".

Examples

Diseases where the cause is seen as wholly or partly idiopathic include:

• Idiopathic pulmonary fibrosis
• Idiopathic pulmonary haemosiderosis
• Idiopathic intracranial hypertension
• Idiopathic chronic fatigue
• Granulomatous prostatitis

Medical advances and this term

Advances inmedical scienceimprove the understanding of causes of diseases and the classification of diseases; thus, regarding any particular condition or disease, as more root causes are discovered and as events that seemed spontaneous have their origins revealed, the percentage of cases designated as idiopathic decreases.

Usage of synonyms

The wordessentialis sometimessynonymouswithidiopathic(as inessential hypertension,essential thrombocythemia,andessential tremor) and the same is true ofprimary(as inprimary biliary cholangitis,orprimary amenorrhea), with the latter term being used in such cases to contrast withsecondaryin the sense of "secondary to [i.e., caused by] some other condition." Another, less common synonym isagnogenic(agno-,"unknown" +-gen,"cause" +-ic).

The wordcryptogenic(crypto-,"hidden" +-gen,"cause" +-ic) has asensethat is synonymous withidiopathicand a sense that is contradistinguished from it. Some disease classifications prefer the use of the synonymous termcryptogenic diseaseas incryptogenic stroke,and cryptogenicepilepsy.The use of cryptogenic is also sometimes reserved for cases where it is presumed that the cause is simple and will be found in the future.

Somecongenital conditionsare idiopathic, and sometimes the wordcongenitalis used synonymously withidiopathic;but careful usage prefers to reserve the wordcongenitalfor conditions to which the literal sense of the word applies (that is, those whose pathophysiology has existed since theneonatalperiod).

Syndrome without a name

The termsyndrome without a name(SWAN)is used "when a child or young adult is believed to have a genetic condition and testing has failed to identify its genetic cause". It is believed that "about half (50%) of children withlearning disabilitiesand approximately 60% of children with congenital disabilities (disabilities which are apparent from birth) do not have a definitive diagnosis to explain the cause of their difficulties ".

See also

• Diagnosis of exclusion
• Embolic stroke of undetermined source
• Functional disorder
• Idiosyncratic drug reaction
• Fever of unknown origin

External links

• The dictionary definition ofidiopathic diseaseat Wiktionary