What Is Sepsis?

Sepsis, or “blood poisoning”, is a dangerous and potentially fatal disease that can ultimately cause organ failure, impaired blood flow to vital organs, and abnormal blood clotting which may damage tissues.

Most commonly, sepsis originates from bacterial, parasitic, fungal, or viral infections with bacterial infections being the most common origin. Typically, the immune system fights against foreign invaders such as bacteria and viruses with white blood cells. However, sepsis occurs when the immune system overreacts, releasing pro-inflammatory cytokines, chemicals that induce an immune response, into the blood that triggers inflammation throughout the body. The result is an extremely serious condition that is often much worse than the original infection.

Severe sepsis can lead to what is known as septic shock. When sepsis occurs, blood pressure often falls due to the expansion of blood vessels. When the blood pressure falls too low, the development of septic shock is more likely. Additionally, inflammation can cause blood to clot and low blood pressure can reduce blood flow, which together causes organs to receive less blood. Organs receiving little oxygen, adversely affecting their function, also contributes to the development of septic shock.

Eventually, septic shock can lead to multiple organ dysfunction syndrome (MODS). When organ systems receive little oxygen, as is the case during septic shock, the organs can no longer function and end up failing. MODS is characterized by the failure of two or more organ systems. Once someone has MODS, the mortality rate is extremely high, often ranging from 45-70%.