To check for tuberculosis infection, you should visit a hospital and have a CT scan of the chest to determine if there are any foci of tuberculosis infection in the lungs. If no obvious lesions are found or if lesions are present but the diagnosis of tuberculosis is not confirmed, further screening can be done by tuberculin test, or PPD test. If there is coughing and sputum, sputum smear and sputum culture can also be used to look for Mycobacterium tuberculosis, which is also the gold standard for the diagnosis of TB. If the above tests are not clear, fiberoptic bronchoscopy and bronchoalveolar lavage tests can be performed to look for Mycobacterium tuberculosis, and if the patient has a limited lesion in the lung, a small amount of lung tissue can be removed by lung puncture and sent for examination for Mycobacterium tuberculosis. Through these means, most patients can be screened for TB infection.