How to say "complication" in Japanese

• 葛藤かっとうCommon
  noun, suru verb, intransitive verbCovers complication as entanglement: conflicting emotions, interests, or duties pulling against each other. It is really a word for conflict and discord, so use it for tangled human situations, not medical ones.
  父ちちと私の葛藤かっとうに、彼かれは気付きづいていないようです。↗

  He seems not to be aware of the conflict between my father and me.
• 紛糾ふんきゅうCommon
  noun, suru verb, intransitive verbDescribes a situation or discussion that has become tangled and confused — the confusion and disorder side of complication. It points to affairs thrown into a muddle rather than to inner feelings or illness.
• 合併症がっぺいしょうCommon
  nounThe medical complication: an additional disease or condition that arises alongside the main illness. When English 'complication' appears in a medical context, this is the word you want.
• 交錯こうさくCommon
  noun, suru verb, intransitive verbReally describes things crossing and mingling — feelings or elements interwoven. As 'complication' it is marginal: use it when the point is intertwined elements, not when you mean trouble or confusion.
• 併発へいはつCommon
  suru verb, transitive verb, intransitive verb, no-adjectiveFor illness: the fact of a disease breaking out concurrently with another, rather than the resulting condition itself. It stresses coincidence and concurrence — two troubles occurring at the same time.

Choose 合併症 for a medical complication and 併発 for an illness breaking out alongside another; 葛藤 suggests tangled conflict of feelings or interests, 紛糾 a situation thrown into confusion, and 交錯 elements crisscrossing and mingling.

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

• 葛藤かっとうconflict
• 紛糾ふんきゅうcomplication
• 合併症がっぺいしょうcomplication
• 交錯こうさくmixture
• 併発へいはつconcurrence
• いざこざtrouble
• 錯雑さくざつcomplication
• 複雑化ふくざつかcomplication
• 併発症へいはつしょうcomplication (in illness)
• コンプリケーションcomplication
• もつれcomplication