What does idiopathic mean?
Idiopathic is an adjective used primarily in medicine to describe a disease or condition that arises without an identifiable cause. Doctors may use it when examinations and tests reveal no underlying explanation, as in “idiopathic pulmonary fibrosis,” a form of lung scarring whose cause is not known. The word can also mean peculiar to an individual or case, although this broader sense is less common today. Idiopathic differs from a condition with a known cause, which may be described as secondary or acquired. In everyday conversation, the word can sound highly technical, so speakers often prefer plainer expressions such as “of unknown cause” or “unexplained.” Its unusual history makes it especially memorable: it combines the Greek idios, meaning “one’s own” or “peculiar,” with pathos, meaning “suffering” or “disease.”
adjectiveIn medicine, of a disease or condition: arising without an identifiable cause or known underlying cause. More broadly, peculiar to a particular person, case, or situation.
- In medicine, of a disease or condition: arising without an identifiable cause or known underlying cause.
- More broadly, peculiar to a particular person, case, or situation.
"Her idiopathic pulmonary fibrosis causes progressive scarring of the lungs for reasons that remain unclear."
"The doctors classified her condition as idiopathic because no cause could be identified."
"The project suffered an idiopathic failure that engineers were unable to explain."
Idiopathic comes from Greek words meaning “one’s own” and “suffering,” a remarkably literal history for a term describing a disease whose cause cannot be identified.
Reviewed by Deb Chak, Editor. AI-assisted content curated by RJS Tech Solutions LLP.
Where does idiopathic come from?
Idiopathic comes from Greek ἰδιοπαθής (idiopathēs), formed from ἴδιος (idios), meaning “one’s own” or “peculiar,” and πάθος (pathos), meaning “suffering” or “disease.” Its literal sense is approximately “one’s own suffering” or “peculiar disease.” The word entered English in the 17th century and became especially established in medical usage for conditions arising without a known cause.
Related word forms
How idiopathic is actually used
The word is most common in formal medical and scientific contexts. In general use, it can sound deliberately technical, so it may sound more natural to say “of unknown cause” when that is the intended meaning.
Easily confused with idiopathic
Idiopathic refers chiefly to a disease or condition arising without a known cause, whereas idiosyncratic means highly individual, unusual, or characteristic of a particular person.