Which shock is characterized by widespread vasodilation and a relative hypovolemia not primarily due to blood loss?

• A. Distributive Shock
• B. Septic Shock
• C. Cardiogenic Shock
• D. Hypovolemic Shock

Answer: (A)

Distributive shock is defined by widespread vasodilation that dramatically lowers systemic vascular resistance and causes blood to pool in the peripheral vessels. Even if the total amount of fluid in the body isn’t reduced, the expanded vascular space creates a state of relative hypovolemia, so tissues receive less blood flow and perfusion drops.

A common example is septic shock, where inflammatory mediators cause both dilated vessels and increased capillary leak, worsening the effective circulating volume. This contrasts with other shocks: hypovolemic shock comes from actual loss of intravascular volume (bleeding, dehydration), cardiogenic shock from the heart’s inability to pump effectively, and while septic shock fits distributive criteria, the key feature across distributive types is the widespread vasodilation leading to poor perfusion rather than a primary loss of blood volume.