Which shock is caused by loss of whole blood or dehydration?

• A. Cardiogenic shock
• B. Septic shock
• C. Relative hypovolemia
• D. Hypovolemic shock

Answer: (D)

Loss of circulating blood volume from bleeding or dehydration directly reduces venous return and preload, so the heart can’t eject enough blood to maintain tissue perfusion. This leads to a fall in stroke volume and cardiac output, with signs of shock as organs don’t receive enough oxygen and nutrients. That’s why the scenario described fits hypovolemic shock best: it’s caused by a true loss of fluid volume, whether from blood loss or fluid depletion.

Cardiogenic shock, by contrast, comes from the heart’s inability to pump effectively, not from a lack of volume. Septic shock involves infection that causes widespread vasodilation and capillary leakage, not simply volume loss. Relative hypovolemia refers to a situation where the circulating volume is adequate but the vascular compartment is effectively larger or more leaky, so perfusion falls without actual fluid loss.