No acute abnormality means the scan did not show a new urgent problem at the time it was done.
This is a report phrase, not a symptom. A person can still have pain or other symptoms even if the scan does not show a new emergency problem.
Imaging helps rule out urgent causes such as fresh bleeding, major fracture, new blockage, or another emergency problem, even when symptoms are still real.
Radiologists use this phrase to say that, based on the scan, there is no obvious new emergency finding at that moment.
The next step may be treatment of symptoms, further examination, another test, or follow-up if symptoms continue.
This entry explains the word. If it appeared on your report, the next step is getting that report interpreted for your case.