Sepsis is a serious medical condition that is characterized by a whole-body inflammatory state (called a systemic inflammatory response syndrome or SIRS) and the presence of a known or suspected infection. The body may develop this inflammatory response to microbes in the blood, urine, lungs, skin, or other tissues. An incorrect layman's term for sepsis is blood poisoning, more aptly applied to Septicemia, below.

Septicemia (also septicaemia or septicæmia [sep⋅ti⋅cæ⋅mi⋅a]

Sepsis is usually treated in the intensive care unit with intravenous fluids and antibiotics. If fluid replacement is insufficient to maintain blood pressure, specific vasopressor drugs can be used. Artificial ventilation and dialysis may be needed to support the function of the lungs and kidneys, respectively. To guide therapy, a central venous catheter and an arterial catheter may be placed. Sepsis patients require preventive measures for deep vein thrombosis, stress ulcers and pressure ulcers, unless other conditions prevent this. Some patients might benefit from tight control of blood sugar levels with insulin (targeting stress hyperglycemia), low-dose corticosteroids or activated drotrecogin alfa (recombinant protein C).