1
have a backache
指一次具体的背痛发作时，backache 是可数名词，前面常用 a。
I have a backache after sitting at the computer all day.
我在电脑前坐了一整天，现在背疼。
背痛；背疼
backaches — plural of backache
先理解核心含义，再看它在真实句子里的用法。
背痛；背疼
Any pain or ache in the back.
I have a backache after sitting at the computer all day.
我在电脑前坐了一整天，现在背疼。
背部任何疼痛或酸痛,即背痛
Any pain or ache in the back.
I often get a backache after sitting for long hours.
长时间坐着后，我经常背痛。
She has had a persistent backache since the accident.
自从那次事故后，她一直有持续的背痛。
You should see a doctor if your backache doesn't go away.
如果你的背痛没有消失，你应该去看医生。
指一次具体的背痛发作时，backache 是可数名词，前面常用 a。
I have a backache after sitting at the computer all day.
我在电脑前坐了一整天，现在背疼。
表示长期、反复的背痛时，backache 常作不可数名词，不带 a。
Many older people suffer from backache.
许多老年人患有背痛。
复数 backaches 强调多次或习惯性的背痛。
She gets backaches whenever she carries a heavy bag.
她每次背很重的包都会背疼。
Not this
I am having a backache.
Use this
I have a backache.
have 表示“患病/疼痛”时是状态动词，不用进行时；正在背痛应说 I have a backache，而不是 I am having a backache。中文没有进行时态区别，学习者容易加 am having。
Not this
I have a backache since yesterday.
Use this
I have had a backache since yesterday.
since 表示“从……起”，与现在完成时连用，说明动作或状态持续到现在；不能用一般现在时。应把 have 改为 have had。
Not this
I have a backache on my back.
Use this
I have a backache.
backache 本身就表示“背部的疼痛”，再加 on my back 既重复又介词错误；直接说 I have a backache 即可。
Focus on the distinctions below. Other candidates are kept compact until a reliable usage note is available.
慢性背痛
He has suffered from chronic backache for years.
他多年来一直患有慢性背痛。
剧烈背痛
She called the doctor because of a severe backache.
她因剧烈背痛而叫了医生。
饱受背痛之苦
Many office workers suffer from backache.
许多办公室职员饱受背痛之苦。
背痛
I have a backache after carrying those heavy boxes.
搬完那些重箱子后，我背痛。
（经常）背痛
He gets backaches when he sits too long.
他坐太久时就会背痛。
治疗背痛的方法
She is looking for a remedy for her backache.
她在寻找治疗背痛的方法。
Use backaches naturally, then get feedback on meaning, tone, grammar, and phrasing.
Revisit a common error or keep this word in your review list.
back(背)+ache(痛)两个词拼成backache：后背在痛，就是背痛。
语域：neutral 常见场景：日常交谈、就医问诊 backache 是中性、常用的普通名词，多用于日常谈论背部疼痛或不适，也常见于就医时的口头描述；在更正式的医学语境中通常会选用更精确的术语。
这些词中 ache、headache、toothache、earache、stomachache 都以 /eɪk/ 结尾，与 backache 押韵；注意 cache 拼写相近但读 /kæʃ/，发音不同。
Dictionary facts from ECDICT, WIKTIONARY.