再発

1. Origins, structure, and basic meaning

• Structure: In 再発 (さいはつ), again 再 and occurrence 発 combine to denote recurrence.
• Basic usage: 再発 is used when an illness or problem returns after previously disappearing or subsiding.

2. Common pitfalls and similar expressions

• Recurrence after an earlier episode
  • It does not fit a first occurrence; the predicate after 再発を supplies prevention, concern, or confirmation.