Sepsis is a life-threatening illness caused by your body’s response to an infection. Your immune system protects you from many illnesses and infections, but it’s also possible for it to go into overdrive in response to an infection.
Sepsis develops when the chemicals the immune system releases into the bloodstream to fight an infection cause inflammation throughout the entire body instead. Severe cases of sepsis can lead to septic shock, which is a medical emergency.
Causes. While any type of infection — bacterial, viral or fungal — can lead to sepsis, the most likely varieties include:
Bloodstream infection (bacteremia)
The incidence of sepsis appears to be increasing in the United States. The causes of this increase may include:
Aging population. Americans are living longer, which is swelling the ranks of the highest risk age group — people older than 65.
Drug-resistant bacteria. Many types of bacteria can resist the effects of antibiotics that once killed them. These antibiotic-resistant bacteria are often the root cause of the infections that trigger sepsis.
Weakened immune systems. More Americans are living with weakened immune systems, caused by HIV, cancer treatments or transplant drugs.
There are more than 1 million cases of sepsis each year, according to the Centers for Disease Control and Prevention (CDC). This type of infection kills more than 258,000 Americans a year.