Good to knowOne result rarely tells the whole story. Your provider looks at your results together with your symptoms, exam, and other tests.
What the test is
Two or more samples are usually drawn from different sites. Results can take 1 to 5 days.
Why it's done
- High fever with chills or shaking
- Possible sepsis
- Possible infection of a heart valve or bone
Getting ready and what happens
- Done before antibiotics when possible.
How the test is done
- Blood is drawn from two different veins into special bottles.
What the results mean
Positive
Identifies the germ and best antibiotic. A single positive with common skin germs may be contamination.
When a result needs quick action
Call 911Fever with confusion, fast breathing, low blood pressure, or cold, mottled skin
Questions to ask your provider
- What do my results mean for me?
- Do I need to repeat this test or have other tests?
Risks
A blood draw is very safe. You may have slight pain or a small bruise where the needle went in.
Related conditions
Related tests
Sources
Last updated 2026-11-13.