What does bacteremia mean?
Bacteremia is the presence of bacteria in the bloodstream, confirmed most often by positive blood cultures. It exists on a spectrum: transient bacteremia can follow ordinary events such as tooth brushing, dental procedures, or minor infections, and is quickly cleared by the immune system in healthy people. Sustained or high-grade bacteremia, however, is a serious finding that may signal a focal infection such as pneumonia, an infected intravenous catheter, or endocarditis, and it can progress to sepsis if untreated. The word derives from Greek roots — bakterion (small rod) and haima (blood) — joined in the nineteenth century as microbiology matured. It is a formal, clinical term found in hospital charts, research literature, and medical education rather than everyday conversation. Understanding bacteremia matters because it underpins how physicians diagnose bloodstream infection, interpret culture results, and decide when aggressive antibiotic therapy is warranted.
nounThe presence of bacteria in the bloodstream, typically detectable by blood culture. It may be transient and harmless or a serious condition that can lead to sepsis.
- The medical condition in which viable bacteria are present in the blood, whether transient and asymptomatic or clinically significant.
- A laboratory finding of bacterial growth in blood cultures, used as a diagnostic marker.
"The patient's persistent fever prompted blood cultures, which confirmed bacteremia caused by Staphylococcus aureus."
"Dental extraction can cause transient bacteremia that resolves without treatment in healthy individuals."
"Intravenous catheters are a common source of nosocomial bacteremia in hospitalized patients."
Rarely pluralized in practice; clinicians more often speak of individual cases or episodes of bacteremia than of multiple 'bacteremias'.
"The study reviewed recurrent bacteremias among immunocompromised patients."
Brushing your teeth too vigorously can cause transient bacteremia — bacteria briefly slip into your bloodstream and your immune system clears them within minutes.
Reviewed by Deb Chak, Editor. AI-assisted content curated by RJS Tech Solutions LLP.
Etymology of bacteremia
Bacteremia combines the Greek-derived noun 'bacterium' (from bakterion, 'small rod') with the combining form '-emia', from Greek haima meaning 'blood'. The compound was formed in the nineteenth century alongside other '-emia' terms such as anemia and leukemia, as germ theory and blood-culture techniques made it possible to identify microorganisms circulating in the blood. Its cognates include the broader family of hematological terms built on '-emia', such as toxemia, hypoglycemia, and hyperglycemia.
Related word forms
How bacteremia is actually used
Bacteremia is a technical term used almost exclusively in medical and scientific contexts. Clinicians increasingly distinguish it from sepsis, since bacteremia describes the laboratory finding while sepsis describes the body's dysregulated response to infection. The related older term 'septicemia' has largely fallen out of favor in modern clinical usage.
Easily confused with bacteremia
Septicemia is an older term for blood poisoning with systemic illness (now usually called sepsis), whereas bacteremia refers strictly to the presence of bacteria in the blood, which may occur without severe symptoms.
Viremia is the presence of viruses (not bacteria) in the bloodstream.
Fungemia is the presence of fungi (such as Candida) in the bloodstream rather than bacteria.