"Blood poisoning" isn't a medical term. But as the term is often used, it refers to the presence of bacteria in the blood (bacteremia) or an infection in the blood — and not a poisonous substance in the blood. But bacteremia and infection can potentially progress to sepsis and septic shock — serious illnesses that need prompt medical attention.

When to see a doctor

If you recently had a medical or dental illness or procedure, such as a wound infection or tooth removal, or stayed in the hospital, and have any of the following signs and symptoms, see your doctor right away:

• Sudden fever
• Chills, with or without shaking

A diagnosis of bacteremia or infection is confirmed by blood cultures.

During treatment, you'll need to stay in the hospital and have IV antibiotics. Without prompt treatment, bacteremia or infection can spread to other areas such as heart valves or other tissues. Or it can progress to severe sepsis and septic shock, which may be life-threatening.