1) Shock is a condition where the cardiovascular system fails to adequately perfuse tissues due to impaired cardiac pump function, circulatory issues, or low blood volume.
2) The main types of shock are hypovolemic (low blood volume), cardiogenic (impaired heart function), and distributive (blood vessel problems).
3) Hypovolemic shock results from internal or external fluid loss leading to decreased circulating volume and tissue perfusion. Cardiogenic shock occurs due to impaired left ventricular pumping ability despite normal blood volume.