In Class 4 hypovolemic shock, blood volume lost is?

• A. >40%
• B. 30-40%
• C. >50%
• D. 15-30%

Answer: (A)

Class IV hypovolemic shock is defined by massive blood loss, specifically more than 40% of the total blood volume. In an average adult (~5 liters), that means roughly 2 liters or more have been lost. When this much volume is gone, venous return drops sharply, preload falls, cardiac output cannot be maintained despite compensatory tachycardia, and perfusion to vital organs collapses. Clinically, you’d see severe hypotension, altered mental status, cold clammy skin, a rapid weak pulse, and very low urine output. Earlier classes involve smaller percentages of blood loss and milder signs, so exceeding about 40% marks the most severe category.