headache

Compared meaning: something that causes worry (noun).

比较义项：因某事而产生的担心、忧虑（名词）。

• worry

  The plain, everyday word for felt anxiety about anything, large or small; common in casual phrases like 'don't worry' or 'no worries', and pairs naturally with 'about'.

  最普通、最口语化的说法，指对任何大小事情的担心；常出现在“别担心”“不用担心”等说法里，习惯与“about”搭配。

  His only worry was whether the flight would leave on time.

  他唯一担心的是航班是否会准时起飞。

• concern

  More formal than worry; names one specific issue a person consciously focuses on or feels responsible for, typical of professional or serious contexts.

  比worry更正式，通常指某人自觉关注或觉得自己有责任处理的某个具体问题，常见于正式或严肃场合。

  Her main concern is finishing the project on time.

  她最担心的是能否按时完成这个项目。

• headache 本词

  Informal and exaggerated; describes an annoying, recurring practical hassle rather than deep emotional anxiety, often used for paperwork or minor troubles.

  口语化且带夸张色彩，指令人厌烦、反复出现的实际麻烦事，而非深层的情绪焦虑，常用于手续、琐事等场合。

  Renewing my visa every year is such a headache.

  每年续签证都是一件令人头痛的事。

Worry, concern, and headache all name something that causes anxiety, but the tone differs. Worry is the plain word for anything that troubles a person. Concern is more formal, naming one specific issue someone focuses on. Headache is informal and exaggerated, describing an annoying hassle.

这三个词在“因某事产生的担心、忧虑”这一意义上相近，但语气和正式程度不同：worry最口语、最宽泛；concern更正式，通常指某个具体关注的问题；headache本义是“头痛”，这里转指令人厌烦的麻烦事，语气带夸张。这里不比较concern作动词表示“涉及、关系到”的用法，也不比较headache表示生理疼痛“头痛”的本义。