noun, noun which may take the genitive case particle 'no'
cause of a disease; pathogen; etiology
Refers to the origin or cause of an illness, including pathogens, genetic factors, or environmental triggers. Used in medical and general contexts.
この病気の病原はまだ特定されていない。
The cause of this disease has not yet been identified.
病原菌が体内に侵入すると感染症を引き
When pathogenic bacteria enter the body, they cause infectious diseases.
Compound of 病 (disease) and 原 (origin, source). The spelling 病源 uses 源 (source) with a similar meaning, but 病原 is the standard form.