Lab tests for tuberculosis

Tuberculosis Screening can look for an immune response suggesting infection, but it does not by itself show whether disease is active or where it is located. If lung disease is suspected, a clinician may request mucus coughed up from the lungs for laboratory analysis and a Chest X-Ray to look for changes. Testing may be expanded when infection outside the lungs is possible. A persistent cough, fever, night sweats, or swollen glands can occur with tuberculosis, but each symptom has other possible causes. HIV Infection and some medicines can alter risk and the clinical assessment.

Tell the clinician about close contact with tuberculosis, previous testing or treatment, travel or residence in areas where it is common, vaccination history, and medicines that affect immunity. Follow instructions for producing a sputum sample; saliva alone may not be suitable. Keep appointments even when a screening result is positive but you feel well, because further assessment may be needed. If active disease is suspected, follow infection-control advice about masks, ventilation, and close contact while results are pending. Do not begin or stop treatment without specialist guidance.

Seek urgent care for severe breathlessness, coughing up blood, chest pain, confusion, fainting, or rapidly worsening illness. Arrange prompt medical review for a cough that persists, unexplained fever, drenching night sweats, weight loss, or new swollen glands, particularly after close exposure or with reduced immunity. A normal initial test does not remove the need for review when symptoms continue.

Ask which test is being used and whether it checks exposure or active disease, how to collect a sputum sample, when results are expected, and whether close contacts need screening. Clarify what precautions to follow and which symptoms should prompt immediate help.