Sputum Culture: About This Test

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The lungs

What is it?

Sputum (say "SPYOO-tum") is a thick fluid, or mucus, made in the lungs and in the airways leading to the lungs. A sputum culture tests a sample of sputum to see if it contains germs. The sputum is placed in a container with substances that help germs grow.

Why is this test done?

A sputum culture is done to:

  • Find and identify bacteria that are causing a lung infection such as pneumonia or tuberculosis.
  • Identify the best antibiotic to treat the infection.
  • Check to see how treatment is working.

How can you prepare for the test?

  • Don't use mouthwash before this test.

What happens during the test?

  • You rinse your mouth with water, take a deep breath, and then cough deeply to produce a sample of sputum.
  • The health professional collecting the sample may tap on your chest to help loosen the sputum in your lungs before you cough.
  • If you still have trouble coughing up a sample, you may be asked to inhale an aerosol mist to help you cough.

What else should you know about the test?

  • Some types of bacteria grow quickly in a culture, and some grow slowly. Test results may take from 1 day to several weeks

How long does the test take?

  • The test will take a few minutes.

What happens after the test?

  • 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 or nurse call line 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 https://www.healthwise.net/patientEd

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