Patients (and even some practitioners) use the term acute to describe a nasty or severe pain.
Strictly speaking, in medical parlance, we should use the term to distinguish new pains or problems from old ones.
So a brand new or recent onset problem is acute. Even weeks or a few months later it can still be labelled acute, but if it persists beyond that, is re-labelled chronic.
Practitioners mainly (and correctly) use the term acute in this temporal way.
However, the way in which patients use the term acute makes a kind of sense given that the worst pain is generally at the very beginning of an episode (up to 2-3 days after onset).