Illustration of parts of the body susceptible to dangerous hematomas in hemophiliacs that require instant medical attention. Hematomas of the pharynx, neck, the floor of the mouth can lead to asphyxia. Hematomas of the psoas muscle can simulate appendicitis, lead to anemia or compress the crural nerve. Hematomas of the buttocks, calf, popliteal fossa, the forearm and wrist can lead to vascular or neurological compression which can lead to paralysis. Hematomas of the retroperitoneal and peritoneal areas.