Translation guide
The English word "complications" can refer to medical issues, factors that make a situation harder, or a state of complexity. This guide helps learners choose the right Japanese expression for each meaning.
To refer to secondary diseases or conditions that arise during an illness or after a procedure.
The standard medical term for a complication arising from a disease or treatment.
手術後に合併症が起こった。
Complications occurred after the surgery.
糖尿病の合併症に注意が必要だ。
You need to watch out for complications of diabetes.
Also means a secondary disease, but less common than 合併症. Often used in medical contexts.
インフルエンザの併発症として肺炎がある。
Pneumonia is a complication of influenza.
To describe problems, obstacles, or additional issues that complicate a plan or situation.
A general word for 'problem' or 'issue'. Often used in the plural 問題点 (problems/issues) to mean complications.
計画にはいくつかの問題が生じた。
Several complications arose with the plan.
予期しない問題が発生した。
Unexpected complications occurred.
Literally 'complex factors'. Used when emphasizing the intricacy of the situation.
この件には複雑な要素が多い。
There are many complications in this matter.
A casual way to say 'complicated things' or 'troublesome matters'. Used in informal speech.
ややこしいことが起きて、旅行に行けなくなった。
Some complications came up and I couldn't go on the trip.
To refer to the quality of being intricate, involved, or difficult to understand.
The noun form of 'complex', meaning complexity or complicatedness.
この問題の複雑さには驚かされる。
I'm amazed at the complications of this problem.
Refers to complexity that is troublesome or bothersome, often with administrative or procedural nuances.
手続きの煩雑さが問題だ。
The complications of the procedure are a problem.
The adjective 複雑 (ふくざつ) means 'complex', but using it as a noun to mean 'complications' is unnatural. Use 複雑さ for the state of being complicated, or 問題 for specific issues.
Both mean a secondary disease, but 合併症 is the everyday medical term, while 併発症 is more technical and less common. Stick with 合併症 in most contexts.
手術はうまくいったが、合併症があった。
The surgery went well, but there were complications.
プロジェクトでいくつか問題が起きた。
We ran into some complications with the project.