A sputum test is a medical examination of mucus that is coughed up from the lungs. This test helps doctors diagnose respiratory conditions, such as pneumonia, tuberculosis, and other lung infections. Patients are usually asked to take a deep breath and then cough deeply to produce a sample, which is collected in a sterile container. The collected sputum is then analyzed in a laboratory for the presence of bacteria, viruses, or abnormal cells. Results from the sputum test can provide valuable information about the type of infection or disease, guiding appropriate treatment options for the patient.