How to say "recurrence" in Japanese

• 再発さいはつJLPT N1approx.Common
  noun, suru verb, intransitive verbThe recurrence of something undesirable after it had been resolved or recovered from, especially the return of an illness or symptoms; relapse. Typical when talking about cancer coming back or a problem recurring.
  １９５５年ねんにガンが再発さいはつし、彼女かのじょは１９５６年ねんに４２歳さいで亡なくなった。↗

  In 1955, the cancer returned and she died in 1956 at the age of 42.
• 回帰かいきCommon
  noun, suru verb, intransitive verbA return or recurrence in a cyclical or technical sense, such as periodic return, regression, or recurrence in mathematics and statistics. Less about a specific bad event recurring; the nuance is recurrence as part of a cycle or pattern.
• 再燃さいねんCommon
  noun, suru verb, intransitive verbA recurrence framed as something flaring up again after dying down, like a fire rekindling; also revival. Often suits renewed controversy or activity, but for a disease's return 再発 is usually the word you want.
  その問題もんだいが再燃さいねんした。↗

  The problem has come to the fore again.

Use 再発 for something unwanted recurring after recovery (illness, problems), 回帰 for cyclical or mathematical return, and 再燃 mainly for something dying down and flaring up again.

Usage comparisons are AI-assisted and cross-checked by multiple models; for study reference only

• 再発さいはつreturn
• 回帰かいきreturn (to)
• 再燃さいねんrecurrence
• 再帰さいきreturning again