It is sometimes difficult to confirm the diagnosis of tuberculosis. There are many tests that can be used to assist in the diagnosis of tuberculosis in clinical practice, but these tests have certain limitations that make the diagnosis of tuberculosis difficult, such as sputum antacid staining or sputum tuberculosis culture. If these results are positive, the diagnosis of tuberculosis can basically be confirmed, but many patients with tuberculosis have negative results from the above tests. Combined DNA testing is also helpful in diagnosing TB, but many patients with TB are also negative for combined DNA testing. Chest CT or chest radiographs can also be helpful in the diagnosis of TB, but in many cases, relying on chest CT or chest radiographs neither confirms nor excludes the diagnosis of TB. Tuberculosis gamma interferon release test and tuberculin test are helpful in the diagnosis of tuberculosis, but these results are positive and do not confirm the diagnosis of active tuberculosis. Negative results do not rule out active tuberculosis. In summary, the diagnosis of TB is sometimes very difficult and may even require a fiberoptic bronchoscopic lung biopsy or percutaneous puncture lung biopsy for pathologic examination to further assist in the diagnosis.