Sepsis

Sepsis is not the infection itself. It's what happens when the body's own response to an infection becomes dysregulated, in other words out of proportion, and ends up damaging the body's own tissues to the point of causing organ dysfunction, meaning the organs stop working properly, which puts the person's life at risk.

First, cells recognize the pathogen, the microbe causing the infection, and switch on the defenses. The leukocytes, which are the white blood cells, are activated, then complement, a group of defense proteins, and then coagulation. That chain ends in cell death, and the dying cells release more toxic substances that set the inflammation off again. A fire that feeds on what it burns. If nothing stops it, the cascade can sustain itself.

And here is the key point: having an infection is not the same as having sepsis. Two things make the difference: the body's response is dysregulated, and the organs have started to fail.