Septic shock occurs most often in the very old and the very young. It also occurs in people with underlying illnesses. Any bacterial organism can cause septic shock. Fungi and (rarely) viruses may also cause this condition. Toxins released by the bacteria or fungus may cause direct tissue damage, and may lead to low blood pressure and/or poor organ function. These toxins also produce a vigorous inflammatory response from the body which contributes to septic shock.

Risk factors include underlying illnesses, such as diabetes; hematologic cancers (lymphoma or leukemia); and other malignancies and diseases of the genitourinary system, liver or biliary system, and intestinal system. Other risk factors are recent infection, prolonged antibiotic therapy, and having had a recent surgical or medical procedure. See also:

• Meningococcemia
• Waterhouse-Friderichsen syndrome
• DIC (disseminated intravascular coagulation)
• Multiple organ dysfunction syndrome (MODS)
• ARDS