What are the three primary categories of shock etiology?

• A. Cardiogenic shock
• B. Infection, toxin, trauma
• C. Heart failure, lung disease, kidney failure
• D. Pump problems, pipe problems, fluid problems

Answer: (D)

Think of shock etiology in terms of three broad categories: pump problems, pipe problems, and fluid problems. This framework helps you quickly identify why perfusion is failing.

A pump problem means the heart isn’t able to push blood effectively, so cardiac output drops. This isn’t just one specific disease; it’s the general idea that the heart’s pumping ability is compromised, as in myocardial injury or severe arrhythmias.

A pipe problem refers to the blood vessels themselves not carrying blood properly. Vascular tone can be pathologically altered, or there can be obstruction, causing inadequate distribution of blood. Distributive shock from widespread vasodilation is a classic example, where the pipes are too large or too loose for the circulating volume.

A fluid problem involves not enough circulating blood volume to fill the vascular system, such as from hemorrhage, dehydration, or extensive burns. When volume is depleted, there’s insufficient preload to sustain adequate perfusion.

The other options don’t capture this three-way framework. They may name a specific type of shock or list organ failures, but they don’t convey the broad etiologic categories that explain most shock presentations.