Blood Culture Test

Why am I having this test?

A blood culture test is performed to see if you have an infection in your blood (septicemia). This test may be ordered if you have fever, chills, nausea, or fatigue, and your health care provider suspects septicemia.

What is being tested?

Your sample will be tested for the presence of bacteria or fungi that can cause septicemia.

What kind of sample is taken?

A person having a blood sample taken from the arm.

At least two blood samples from two different veins are required for this test. The blood samples are usually collected by inserting a needle into a blood vessel. Two samples are taken because:

There is a better chance of finding the infection with more than one sample.
There is a better chance of an accurate result. Despite good cleaning, germs can remain on the skin where the blood is collected and could lead to a positive result even when you do not have the condition. If this happens, another test is done.

How do I prepare for this test?

Tell your health care provider if you are taking antibiotic medicine. It is recommended that blood samples be collected before starting this medicine. If blood cultures are performed while you are on an antibiotic, the blood samples should be collected shortly before you take a dose of the medicine.

How are the results reported?

Your test results will be reported as either positive or negative. For this test, a normal finding is a negative blood culture.

What do the results mean?

A positive blood culture test may mean that you have septicemia or blood poisoning caused by bacteria or fungi. Septicemia can indicate a serious infection.

Talk with your health care provider about what your results mean.

Questions to ask your health care provider

Ask your health care provider, or the department that is doing the test:

When will my results be ready?
How will I get my results?
What are my treatment options?
What other tests do I need?
What are my next steps?

Summary

A blood culture test is performed to see if you have an infection in your blood (septicemia).
At least two blood samples from two different veins are required for this test. This gives a better chance of finding an infection and getting an accurate result.
The normal result for this test is a negative blood culture. A positive result may mean that you have septicemia.
Talk with your health care provider about what your results mean.

This information is not intended to replace advice given to you by your health care provider. Make sure you discuss any questions you have with your health care provider.