• Definition

    Sepsis is a severe illness in which the bloodstream is overwhelmed by bacteria.

    Alternative Names

    Systemic inflammatory response syndrome (SIRS)

    Causes, incidence, and risk factors

    Sepsis is caused by a bacterial infection that can begin anywhere in the body. Common places where an infection might start include:

    • The bowel (usually seen with peritonitis)
    • The kidneys (upper urinary tract infection or pyelonephritis)
    • The lining of the brain (meningitis)
    • The liver or the gall bladder
    • The lungs (bacterial pneumonia)
    • The skin (cellulitis)

    In children, sepsis may accompany infection of the bone (osteomyelitis). In hospitalized patients, common sites of infection include intravenous lines, surgical wounds, surgical drains, and sites of skin breakdown known as bedsores (decubitus ulcers).