"I have a backache" 是表达背疼的常用英语表达。 "Backache" 是由两个单词 "back" 和 "ache" 组成的合成词，"back" 意思是 "背部"，"ache" 意思是 "疼痛"。所以 "backache" 意思就是 "背部疼痛"。
例句1:
"I have a backache. I think I need to pe down for a while."
我背疼了。我想我需要躺一会儿。
例句2:
"I've been having a backache for a few days. I should probably see a doctor."
我这几天一直背疼。我应该去看医生了。
例句3:
"I can't stand up straight because of my backache."
因为背疼我不能直立。