Idiopathic is an adjective used primarily in medicine meaning arising spontaneously or from an obscure or unknown cause. From Greek ἴδιος, idios (one's own) + πάθος, pathos (suffering), it means approximately "a disease of its own kind". It is technically a term from nosology, the classification of disease. 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 be idiopathic.
With some medical conditions, the root cause for a large percentage of all cases has not been established—for example, focal segmental glomerulosclerosis or ankylosing spondylitis; the majority of these cases are deemed idiopathic. With other conditions, idiopathic cases account for only a small percentage (for example, pulmonary fibrosis). Regarding a particular condition or disease, as more root causes are discovered the percentage of cases designated "idiopathic" decreases.
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- Daskalakis N, Winn M (2006). "Focal and segmental glomerulosclerosis". Cell Mol Life Sci 63 (21): 2506–11. doi:10.1007/s00018-006-6171-y. PMID 16952054.
- "Medical Encyclopedia: Idiopathic pulmonary fibrosis". MedlinePlus. Retrieved 2007-02-13.
- Asimov, Isaac (1963). The Human Body: Its Structure and Operation.. Houghton Mifflin. p. 179. ISBN 0-395-07350-2.