My sister has a fat embolism. what does this mean?

FractureComplication: This is almost always preceded by a long-bone fracture, the theory being that fat from bone marrow (and other harmful particles) get into the veins of the bone and travel to the lung. The body's reaction to these particles is what causes most of the trouble, causing tissues to swell and decreasing the movement of oxygen from the lungs into the blood.

If true, serious: Fat embolism is usually due to trauma with disruption of long bones like the femur, exposure of the fat in the marrow to the blood space, & then causing hematologic havoc like diffuse clotting and then a very serious condition called disseminated intravascular coagulation that consumes the proteins needed to clot, so difficult to control bleeding results. This is a big deal, so urgent care needed.