How to tell apart mild sepsis from severe?

Organ failure: Sepsis is defined by signs of infection, including fever, elevated white cell count, elevated heart rate or respiratory rate. ( paradoxically abnormally low body temp ( hypothermia) or low white cell count can also be signs of sepsis. If there is additional signs of organ or system failure ( low blood pressure, decreased production of urine, changes in mental status, it is severe sepsis.

Organ failure: Sepsis is an inflammatory response (fever, rapid heart rate and/or breathing, increased white blood cell count) plus infection. Severe sepsis is when there is also some organ dysfunction as well: respiratory failure, kidney failure, change in mental status, & low blood pressure are some of the problems that can occur. Most patients with severe sepsis need to be in an intensive care unit.

By symptoms: Mild would be if you had a fever and malaise. Severe requires hospital treatment, IV fluids and sometimes medications to support your blood pressure. It depends somewhat on the source of infection as well.

Severity.: The severity is determined by organ dysfuction. Meaning the level of organ 'failure' and the level of certain labs like a latctic acid. Also related to the type of infection which is causing the sepsis. The more medications required to maintain normal body systems the more severe the sepsis. Severity is sirs -sepsis-severe sepsis-septic shock.