Types of TB tests

A tuberculin skin test places a small amount of material under the skin and requires a trained person to check the reaction at a later appointment. An interferon-gamma release assay is a blood test that measures an immune response to TB-related proteins and does not require a return visit to read the result.

Neither screening test alone confirms that TB disease is active. A clinician may request a Chest X-Ray to look for changes in the lungs and collect sputum for laboratory assessment when symptoms or imaging raise concern. The choice depends on exposure history, symptoms, immune status, previous testing, and local clinical advice.

Tell the clinician about previous TB tests, BCG vaccination if relevant, recent contact with someone who has TB, travel or residence history, immune conditions, pregnancy, and medicines. Ask when a skin test must be read and how the result will be communicated.

If sputum is requested, follow the collection instructions carefully; saliva alone may not be an adequate sample. Keep appointments for reading, imaging, or review. A positive screening result usually leads to further assessment rather than an immediate conclusion about active illness.

Contact a healthcare service promptly for a cough that persists, coughing blood, fever, night sweats, unexplained weight loss, chest pain, or worsening tiredness, especially after known exposure. These symptoms can have several causes, but they need assessment.

Seek urgent care for severe breathing difficulty, significant bleeding when coughing, confusion, or fainting. Follow infection-control instructions if a clinician suspects active TB, including advice about masking and close contact while assessment is underway.

Ask which test is appropriate for your reason for testing, whether you need one test or a combination, when results are expected, and what a positive or negative result can and cannot establish. You can also ask about Tuberculosis Screening and the next step if symptoms continue.