発症

• Reading: はっしょう
• Romaji: hasshou
• Kanji breakdown: 発 (hatsu) — emit, produce, start; 症 (shou) — symptom, condition
• Pronunciation: /haɕ.ɕoː/

Meaning

Onset of an illness; outbreak of symptoms. The point at which a disease first manifests.

A noun and suru-verb describing the moment when symptoms of a disease first appear. Used both transitively (a disease causes onset) and intransitively (symptoms develop). Common in medical reporting and health discussions — 発症する (to develop/manifest) is the standard verb form. Distinguished from 発病 (hatsubyou), which emphasises contracting the disease itself rather than the appearance of symptoms.

Examples

1. インフルエンザは感染してから発症するまで数日かかる。 It takes several days from infection to the onset of symptoms with influenza.
2. 母はアレルギーを急に発症した。 My mom suddenly developed allergies.
3. 発症から治療開始までの時間が回復に影響する。 The time from onset to the start of treatment affects recovery.

Usage Guide

Context: medical, news, health discussions

Tone: serious

Origin & History

From Sino-Japanese: 発 (hatsu, emit/produce) + 症 (shou, symptom/condition). Literally 'producing symptoms' — the emergence of disease signs.

Cultural Context

Era: Modern

Generation: All ages

Social background: Universal