Phase 1 · Understand the Body — Why the disease behaves the way it does.
The One-Line Truth
The whole disease in one chain
Everything on this page exists to explain this line.
An infection escapes local control and triggers body-wide alarm chemicals that make blood vessels leak and relax — pressure falls, organs starve for oxygen, and without fast treatment organs shut down.
A leaking, flooded city under siege
Imagine a walled city (the body) with a healthy water system (blood vessels) that holds pressure and delivers water (oxygen) evenly to every district (organ). An invader (bacteria) breaches the wall and the city guard (immune cells) responds — but instead of a focused local defense, they sound the alarm so loud that EVERY guard floods the streets shouting danger signals (cytokines). These panic signals damage the water pipes themselves: the pipe walls become porous like a sieve (endothelial leak), the pipes lose their structural strength and go slack (vasodilation from nitric oxide), and water gushes out onto the streets faster than it flows through the pipes (distributive shock). Meanwhile, emergency clots block key intersections (microvascular clot formation (thrombosis)), so even the water that stays in the pipes cannot reach the outer neighborhoods (organs). The city's power plants (organs) run dry of water pressure and oxygen, and the whole system collapses despite the tank being full — the delivery is broken, not the supply.
Surviving Sepsis Campaign International Guidelines for Management of Sepsis and Septic Shock 2021 · Sepsis-3 Consensus Definitions (JAMA 2016) · CDC Sepsis Clinical Information · UpToDate — Evaluation and Management of Suspected Sepsis and Septic Shock in Adults · reviewed 2026-02-28