Blood Culture: About This Test

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What is it?

A blood culture is a test to see what kind of bacteria or fungi are infecting your blood.

Usually, a blood infection occurs with other serious infections. These include infections in your lungs, kidneys, bowels, gallbladder, or heart valves.

You may also get a blood infection if your immune system is weak.

Why is this test done?

A blood culture is done to:

  • Find a bacterial infection that has spread into the blood. These include meningitis and osteomyelitis. They also include pneumonia, kidney infections, and sepsis.
  • Find a fungal infection in the blood. One common type is a yeast infection.
  • Check for endocarditis. This is a bacterial infection on the heart valves.
  • Find the best medicines to kill the bacteria or fungi.
  • Find the cause of an unexplained fever, shock, or other very serious illness.

How do you prepare for the test?

  • In general, there's nothing you have to do before this test, unless your doctor tells you to.
  • Tell your health professional if you took antibiotics recently.

How is the test done?

A health professional uses a needle to take a blood sample, usually from the arm. Blood may be taken from two or three places on your body. Or it may be taken at two different times a few hours apart.

What happens after the test?

  • If bacteria are found in the culture, the lab will likely test your blood again to find the best antibiotic to kill the bacteria.
  • You will probably be able to go home right away.
  • You can go back to your usual activities right away.

Follow-up care is a key part of your treatment and safety. Be sure to make and go to all appointments, and call your doctor if you are having problems. It's also a good idea to keep a list of the medicines you take. Ask your doctor when you can expect to have your test results.

Where can you learn more?

Go to http://www.healthwise.net/patientEd

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Current as of: April 30, 2024

Author: Ignite Healthwise, LLC Staff

Clinical Review Board
All Healthwise education is reviewed by a team that includes physicians, nurses, advanced practitioners, registered dieticians, and other healthcare professionals.

Current as of: April 30, 2024

Author: Ignite Healthwise, LLC Staff

Clinical Review Board
All Healthwise education is reviewed by a team that includes physicians, nurses, advanced practitioners, registered dieticians, and other healthcare professionals.

The Health Encyclopedia contains general health information. Not all treatments or services described are covered benefits for Kaiser Permanente members or offered as services by Kaiser Permanente. For a list of covered benefits, please refer to your Evidence of Coverage or Summary Plan Description. For recommended treatments, please consult with your health care provider.