What does a tuberculosis examination include?

Generally, tuberculosis (TB) evaluation requires a multidimensional approach involving bacteriological, imaging, immunological, and other assessments to confirm diagnosis and assess disease status. Key tests include sputum examination, chest imaging, tuberculin skin test, TB antibody testing, and pleural fluid analysis. Detailed explanations are as follows:

1. Sputum Bacteriology Testing: This is the gold standard for confirming pulmonary tuberculosis and includes sputum smear microscopy and sputum culture. Sputum smear is simple and rapid, allowing initial screening for *Mycobacterium tuberculosis*. Sputum culture offers higher detection sensitivity and enables drug susceptibility testing, providing critical information for treatment planning—especially valuable in suspected cases with negative smears.

2. Chest Imaging: Primarily includes chest CT and chest X-ray. Chest X-ray allows rapid identification of pulmonary abnormalities and provides preliminary assessment of lesion location, extent, and morphology. CT scanning offers higher resolution, clearly revealing small lesions, mediastinal lymph nodes, and pleural involvement, thus aiding early diagnosis and evaluation of disease severity.

3. Tuberculin Skin Test (TST): Involves injecting tuberculin into the forearm and observing the skin reaction after 48–72 hours. A hard swelling (induration) of ≥5 mm at the injection site suggests possible infection with *Mycobacterium tuberculosis*. However, this test cannot distinguish between past and current infection and must be interpreted in conjunction with other diagnostic findings.

4. TB Antibody Testing: Detects antibodies against *Mycobacterium tuberculosis* in blood. A positive result indicates either prior or current infection. While rapid and convenient, this test may yield false-positive or false-negative results and therefore serves only as an auxiliary diagnostic tool—not a standalone criterion for confirmation.

5. Pleural Fluid Analysis: For patients presenting with pleural effusion, fluid is collected via thoracentesis and analyzed through routine, biochemical, and microbiological examinations. If the fluid is exudative and *Mycobacterium tuberculosis* is detected—or if TB-related markers are abnormal—this supports a diagnosis of tuberculous pleuritis.

The selection of TB diagnostic tests should be based on the patient’s symptoms and medical history, and multiple tests are typically used in combination. Individuals suspected of TB infection should promptly seek comprehensive evaluation at professional healthcare facilities. Once diagnosed, they should follow medical guidance for standardized treatment to prevent disease progression and complications.