Fat embolism syndrome occurs when fat enters the blood stream (fat embolism) and results in symptoms. Symptoms generally begin within a day. This may include a petechial rash, decreased level of consciousness, and shortness of breath. Other symptoms may include fever and decreased urine output. The risk of death is about 10%.

Fat embolism most commonly occurs as a result of fractures of bones such as the femur or pelvis. Other potential causes include pancreatitis, orthopedic surgery, bone marrow transplant, and liposuction. The underlying mechanism involves widespread inflammation. Diagnosis is based on symptoms.

Treatment is mostly supportive care. This may involve oxygen therapy, intravenous fluids, albumin, and mechanical ventilation. While small amounts of fat commonly occur in the blood after a bone fracture, fat embolism syndrome is rare. The condition was first diagnosed in 1862 by Zenker.