Difference between "pain" and "ache"

What's the difference between pain and ache?

I often see the two words used (almost) interchangeably. At the same time the phrase "aches and pains" is pretty common, and seems to suggest that the two words aren't exact synonyms.

The dictionary definitions I've seen ("ache is a continuous dull pain") don't really help in understanding many of the usages I've come across, such as this one from the NHS:

Back pain [...] usually feels like an ache

and also this title:

Stomach ache and abdominal pain

It would be particularly interesting to see examples where one of the two words is appropriate when describing physical suffering, and the other isn't.

Solution 1:

This is a difficult question to answer, because both aches and pains are subjective experiences - like colours - which you're unable to share, but assume everybody understands. I would have assumed that every language has words for both ache and pain, so a dictionary would tell you the difference in an instant. But, I would also assume you've done that, so your native language might not (I'm interested to find out what language that is).

An ache is a persistent discomfort, typically dull so that you can try to ignore it, but sometimes all-encompassing, yet not sharp enough to describe as pain. Your legs would ache after a tough run; you would not describe this as pain. You usually get a headache, not a head pain. You would suffer pain when you cut your finger, then experience an ache as the wound heals.

A pain is something more localised, often (but not always) short-lived, and something you'd be less able to ignore.

When you receive an injection, there is a pain as the needle goes in. During the following days, the surrounding area will ache.

There is considerable overlap between the two, and it would be quite acceptable to say "the ache in my shoulder is painful".

Poets and songwriters quite often speak of their heart aching. This fits well with a persistent sense of yearning or melancholy. If they said there was a pain in their heart, it would suggest a quite different emotion.

Describing pain and discomfort is difficult and subjective; I imagine in any language. When a doctor asks you how much something hurts, how can you explain in a reliable way?

Solution 2:

"You shall know a word by the company it keeps." Collocations for adjectives coming immediately before pain: chronic, physical, severe, abdominal, sharp, and great; and for ache: dull, minor, familiar, joint, constant, little, and physical.

More general collocations for pain: feel, cause, pain, chest, chronic, suffer, ease, suffering, and severe; and for ache: pain, feel, muscle, stomach, dull, heart, and body.

Solution 3:

In many contexts the two words are synonymous. I doubt many people who speak of their aches and pains particularly think they're describing two different things, any more than when they say, for example, not in any way, shape, or form.

As @Incognito mentions in a comment, ache often means persistent pain. I would also add that pain often implies more extreme or localised discomfort than ache.

Apart from that, there are all sorts of idiomatic usages that primarily or exclusively use one or the other. A pain in the neck can be applied to a tiresome person, for example, and heartache is so commonly used metaphorically for emotional distress that it's normally written as a single word.

Solution 4:

In one sense, pain and ache are synonyms. However, an ache is a dull, prolonged pain (my legs ached for hours after the hike), while pain can be any type of physical discomfort (I felt a sharp pain when my arm brushed the thorny bush).