Idiopathic describes a condition with what characteristic?

• A. No known cause
• B. Caused by medical treatment
• C. Genetic origin
• D. Infection-related

Answer: (A)

Idiopathic describes a condition with no known cause. It means, after thorough evaluation—history, exam, and tests—no specific etiology has been identified. The label is used when a disease or condition cannot be linked to a recognizable factor such as a medical treatment (which would be iatrogenic), a defined genetic origin, or an infectious agent. That doesn’t necessarily mean there will never be a discovered cause; it reflects the current inability to identify one. Many conditions labeled idiopathic may later have a cause uncovered as knowledge grows, but at the time of labeling, there is no known cause. Examples include idiopathic scoliosis and idiopathic pulmonary fibrosis. Therefore, the characteristic that best fits idiopathic is having no known cause.