Sputum is a thick fluid that is produced in the lungs and in the airways that lead to the lungs. Sputum is different than saliva.

A person who has an infection or disease of the respiratory system may cough up sputum. Some diseases can cause pus, blood, or bacteria to show up in the sputum.

Current as of: August 21, 2015

Author: Healthwise Staff

Medical Review: Adam Husney, MD - Family Medicine & Robert L. Cowie, MB, FCP(SA), MD, MSc, MFOM - Pulmonology