noun
sudden illness; acute illness
Refers to an illness that strikes suddenly and often requires urgent attention. Common in medical and everyday contexts.
彼は急病で入院した。
He was hospitalized with a sudden illness.
急病のため、会議を欠席します。
I will be absent from the meeting due to a sudden illness.
Compound of 急 (sudden, urgent) and 病 (illness). The reading is on'yomi for both characters.