Synopsis

Blood poisoning, medically known as sepsis or septicemia, is a life-threatening condition that arises when the body’s response to a systemic infection triggers widespread inflammation, leading to tissue damage, organ failure, and potentially death. While bacteremia refers to bacteria in the bloodstream, sepsis is the body’s overreactive immune response to that infection.

Sepsis can develop from infections anywhere in the body, including the lungs (pneumonia), urinary tract (UTI), skin, or abdomen. The condition progresses rapidly, making early recognition and treatment critical. Sepsis is more common in elderly individuals, infants, and those with compromised immune systems.

Types:

• Sepsis: Systemic inflammatory response to infection, with signs like fever, increased heart rate, and abnormal white blood cell count.

• Severe sepsis: Sepsis with organ dysfunction (e.g., kidney failure, respiratory distress).

• Septic shock: Sepsis with dangerously low blood pressure unresponsive to fluid resuscitation, leading to multiple organ failure.

Common Causes (Risk Factors):

• Bacterial infections: Especially gram-negative bacteria (E. coli, Klebsiella) and gram-positive bacteria (Staphylococcus, Streptococcus).

• Pneumonia: Infection spreading from lungs into the bloodstream.

• Urinary tract infections (UTIs): Can lead to sepsis, especially in older adults.

• Abdominal infections: Such as appendicitis, diverticulitis, or peritonitis.

• Skin infections: Cellulitis, infected wounds, or surgical sites.

• Compromised immune systems: Cancer, HIV, diabetes, steroid use, chemotherapy.

• Hospitalization: Use of catheters, ventilators, or intravenous lines increases risk.

• Age extremes: Infants and the elderly are more susceptible.

More Severe Causes (Complications):

• Organ failure: Lungs, kidneys, heart, or liver may fail due to inflammation and poor blood flow.

• Septic shock: Blood pressure drops critically low, leading to death if untreated.

• Disseminated intravascular coagulation (DIC): Abnormal clotting and bleeding occur simultaneously.

• Long-term disability: Even with recovery, survivors may experience cognitive issues, chronic pain, or fatigue.

When to See a Doctor or Specialist (Emergency Medicine, Infectious Disease Specialist):

• Fever, chills, rapid heart rate, rapid breathing (signs of sepsis).

• Confusion, disorientation, or drowsiness.

• Decreased urine output, shortness of breath, or low blood pressure.

• Skin mottling, cold extremities, or bluish discoloration.

• Known infection with worsening symptoms or systemic signs.

• Immunocompromised individuals experiencing any signs of systemic infection.

Variant names

Sepsis
Septicemia
Systemic infection
Bacteremia (with systemic response)
Severe systemic inflammatory response syndrome (SIRS)