A sputum culture is a test to detect and identify bacteria or fungi that infect the lungs or breathing passages. Sputum is a thick fluid produced in the lungs and in the adjacent airways. Normally, fresh morning sample is preferred for the bacteriological examination of sputum.

How is a sputum test performed?

You will be asked to cough deeply and spit any phlegm that comes up from your lungs into a special container. The sample is sent to a lab. There, it is placed in a special dish (culture). It is then watched for two to three days or longer to see if bacteria or other disease-causing germs grow.

What will a sputum test show?

A bacterial sputum culture is used to detect and diagnose bacterial lower respiratory tract infections such as bacterial pneumonia or bronchitis. It is typically performed with a Gram stain to identify the bacteria causing a person's infection.