While performing POCUS, it is important to pay attention to what’s happening ‘around’ the kidney as well – sometimes it can save lives. Here are sonographic images obtained from a patient who was found to have a drop in hemoglobin + back pain while on intravenous heparin therapy. Note the large anechoic space pushing aside the right kidney (CT scan included) = a large retroperitoneal hematoma. Blood is anechoic and indistinguishable from any other clear fluid (e.g. ascites, cystic fluid) when fresh. 3 weeks later, note the echogenic content within the hematoma = clotted blood. The patient did well clinically with supportive care.