Blood Poisoning Causes & Risks

Causes

Sepsis occurs when large numbers of infectious agents exist in the blood. Infections with fungi and parasites may lead to sepsis as well. The initial infection often comes from:

A burn , ulcer , or other open wound
Pneumonia
Urinary tract infection

Blood Flow Near Burn Wound

Bacteria can also enter the bloodstream directly from an outside source. A dirty needle used by an IV drug user can cause this type of infection. In some cases, the source of the infection is unknown.

Small amounts of bacteria enter into the blood with dental work or when brushing your teeth. Your body's immune system should fight off these bacteria.

Risk Factors

These factors increase your chance of getting sepsis:

Recent illness or hospital care
Frail health due to extreme age
Poorly working immune system due to:
- Cancer or chemotherapy for treatment of cancer
- Diabetes
- AIDS or another immunosuppressive condition such as an autoimmune disease or an immune deficiency
- Immunosuppressive medications needed after a transplant
Medical treatment with an invasive device
IV drug abuse

Please be aware that this information is provided to supplement the care provided by your physician. It is neither intended nor implied to be a substitute for professional medical advice. CALL YOUR HEALTHCARE PROVIDER IMMEDIATELY IF YOU THINK YOU MAY HAVE A MEDICAL EMERGENCY. Always seek the advice of your physician or other qualified health provider prior to starting any new treatment or with any questions you may have regarding a medical condition. Copyright © 2026 EBSCO Publishing All rights reserved.