SIRS is an inflammatory clinical response that may occur in the absence of infection. When the cause of the systemic (affecting the whole body) inflammatory response is infection, the condition is considered sepsis.
Sepsis is a complication caused by the body's overwhelming and life-threatening response to infection, which can lead to tissue damage, organ failure, and death. A weakened immune system, certain chronic disorders, an artificial joint or heart valve, and certain heart valve abnormalities increase the risk for sepsis. Sepsis has been reported to be the most common cause of death in the noncoronary intensive care unit. Note that it is sepsis (the immune system's response) that is usually the cause of death and not the infection. Therefore, it is crucial that the recognition of sepsis be made as quickly as possible. Delay in identifying sepsis limits the effectiveness of treatment.