Test guide
Sputum Culture
A sputum culture is a test that checks for bacteria or another type of germ that may be causing a respiratory tract infection (an infection in your lungs or airways). Sputum, also known as phlegm, is a thick type of mucus made in your lungs. If you have an infection or chronic illness affecting the lungs or airways, sputum can settle in your lungs, and you may also cough it up
What it is for
A sputum culture is most often used to: A sputum culture is often done with another test called a Gram stain . A Gram stain is a test that checks for bacteria at the site of a suspected infection or in body fluids such as blood or urine. It can help identify the specific type of infection you may have. Source: MedlinePlus, National Library of Medicine. Medical test information is public domain. Source identity and definition checked automatically on 2026-10-18. No individual clinical interpretation or human reviewer is asserted.
Limitations
Reference intervals and interpretation depend on the laboratory, specimen, method and clinical context. This source definition is educational information; it does not establish a diagnosis, product approval or suitability for an individual.
Also known as
- respiratory culture, bacterial sputum culture, routine sputum culture, bacterial culture, respiratory
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