Which type of shock results from widespread vasodilation causing blood pooling and relative hypovolemia?

• A. Septic shock
• B. Anaphylactic shock
• C. Distributive shock
• D. Neurogenic shock

Answer: (C)

Distributive shock happens when widespread vasodilation causes the blood vessels to dilate so much that blood pools in the venous system. Because much of the blood is not returning effectively to the heart, the circulating volume is reduced relative to the size of the vascular space—this is relative hypovolemia. With less blood returning to the heart (lower preload), cardiac output drops and tissue perfusion suffers. The underlying triggers can vary, including infection (septic shock), an allergic reaction (anaphylactic shock), or loss of sympathetic vascular tone (neurogenic shock), but the common thread is the abnormal distribution of blood due to vasodilation, leading to pooling and reduced effective blood volume.