noun, noun or participle which takes 'suru', intransitive verb
onset of illness; falling ill
Refers to the start or outbreak of a disease, often used in medical or formal contexts. Can be used as a noun or with する to mean 'to become ill'.
彼は先月発病して、まだ入院している。
He fell ill last month and is still hospitalized.
発病の原
The cause of the onset of the illness is still unknown.