Acute epididymitis typically presents with a gradual onset of pain and swelling over hours to days, reflecting the progressive inflammatory response of the epididymal tissue. This distinguishes it from conditions with sudden onset, such as testicular torsion. The gradual development allows time for the inflammation to involve adjacent structures, guiding clinical diagnosis and management. Early recognition of this pattern helps differentiate epididymitis from surgical emergencies. Sudden onset within minutes is characteristic of torsion, not epididymitis.

Reference: Campbell-Walsh Urology, Wein et al., 12th Edition.