Hemodynamic echography, including echocardiography, lung ultrasound, and exploration of the inferior vena cava, represents a key point in Emergency Medicine. It improves the diagnostic process and guide therapeutic measures, in particular, in case of non-traumatic shock. It has been shown that diagnosis was enhanced when compared to clinical examination and chest X-ray. It is able to analyze its main components, hypovolemic, obstructive by tamponade, acute right ventricular or left ventricular failure. An international consensus conference recently defined the objectives, the means, the principal results, and the limits of this exam performed by non-cardiologists. The clues to acquire two-dimensional echography and those making the use of more comprehensive Doppler modes are described with their interpretations. They allow to achieve a pathophysiological diagnosis, appropriate treatment, and scalable surveillance to assess their effectiveness. A diagnostic algorithm is proposed based on the literature data.