Spontaneous retroperitoneal hematoma (SRH) is a rare but potentially life-threatening condition characterized by hemorrhage into the retroperitoneal space without an obvious traumatic, iatrogenic, or aneurysmal cause. Although often linked to anticoagulation therapy, hemodialysis, or vascular abnormalities, SRH may also occur in individuals without predisposing factors, posing a significant diagnostic challenge [1, 2].

The retroperitoneum contains numerous vessels, including lumbar arteries, iliac vessels, and venous plexuses, which can bleed. Typical features include sudden abdominal or flank pain, hypovolemia, and occasionally Lenk's triad (pain, palpable mass, shock) [3]. Contrast-enhanced CT is preferred for diagnosis and planning, with angiography used for both diagnosis and intervention [1, 4].

Although exceedingly rare, physical exertion, particularly involving intense Valsalva maneuvers or heavy lifting, has been identified as a trigger for vascular rupture [5]. We report the case of a young, previously healthy male who developed a fatal SRH following strenuous exercise, a presentation highlighting the importance of recognizing exertion-related vascular emergencies.