What should you know about TB testing?

Tuberculosis screening may use a blood test such as an IGRA or a skin test such as the Mantoux test. These tests assess whether your immune system has responded to TB proteins; they do not by themselves show where infection is located or whether it is active.

A positive result usually leads to a clinical review and may be followed by a chest X-ray or other investigations. A negative result may be less reliable in some situations, including recent exposure or a weakened immune system, so the clinician interprets it with your history and symptoms.

Tell the clinician about close contact with someone who has TB, previous testing, travel or residence in areas where TB is common, immune-suppressing conditions or medicines, and any TB vaccine history. Attend the follow-up appointment even if you feel well when a result needs explanation.

If further assessment is requested, complete it promptly. A chest X-ray can look for changes in the lungs, while additional samples may be needed when active tuberculosis is suspected.

Seek medical assessment for a cough lasting several weeks, coughing blood, night sweats, unexplained weight loss, persistent fever, chest pain, or increasing weakness, especially after a known exposure. Seek urgent care for severe breathing difficulty, large amounts of blood, confusion, or collapse.

Ask which test is suitable, when results will be available, whether you need a chest X-ray, and what precautions or treatment are needed if infection is found.