Blood poisoning is a common term sometimes used to describe sepsis – it’s an old term used over generations. A doctor or nurse may say “blood poisoning” because this is a term many people are familiar with. But blood poisoning is not an accurate description of sepsis, and the two terms should not be used interchangeably.
Sepsis is not an infection in and of itself. Sepsis is the body’s life-threatening response to infection. Like strokes or heart attacks, sepsis is a medical emergency that requires rapid diagnosis and treatment.
Sepsis and septic shock can result from an infection anywhere in the body, such as pneumonia, influenza, or urinary tract infections. Worldwide, one-third of people who develop sepsis die. Many who survive are left with life-changing effects, such as post-traumatic stress disorder (PTSD), chronic pain and fatigue, organ dysfunction (organs don’t work properly), and/or amputations.
What happens with sepsis?
Scientists are working on discovering what exactly happens in sepsis. We know the inflammatory response causes problems such as internal blood clotting too much and too fast. This means that parts of the body don’t get adequate blood flow, and the body’s tissues don’t get the nutrients they need. The signs and symptoms of sepsis vary widely and can cause organs to fail, requiring life support.
While we still don’t know why our bodies react this way, we know that sepsis can cause:
- Leakage from the lining blood vessel linings (much like a water hose with holes in it)
- Low blood pressure (hypotension) with reduced blood flow to vital organs
- Small clots throughout the body that prevent nutrients from reaching vital organs
These changes cause a person’s organs to stop working in many cases. Some of the signs include:
- Heart – low blood pressure, fast pulse
- Lungs – low oxygen level, problems breathing
- Kidneys – making very little urine
- Brain – confusion, coma
Sepsis is a medical emergency. If you have any reason to suspect sepsis, it is essential that you seek medical help immediately. If you suspect sepsis, call 9-1-1 or go to a hospital and tell your medical professional, “I AM CONCERNED ABOUT SEPSIS.”

Would you like to share your story about sepsis or read about others who have had sepsis? Please visit Faces of Sepsis, where you will find hundreds of stories from survivors and tributes to those who died from sepsis.
Reviewed January 3. 2023.