Freshmen in high school are screened for tuberculosis, mostly through school physicals. Tuberculosis is a chronic infectious disease caused by Mycobacterium tuberculosis infection, which can involve multiple internal organs, and timely screening can help in early diagnosis and treatment. Tuberculosis screening does not differ by age or gender, and is mostly performed through clinical symptoms, laboratory tests and imaging examinations: 1. 2. Laboratory tests: The main screening methods are sputum smear, drug sensitivity test and blood test. The sputum smear test detects the presence of tuberculosis bacteria in the sputum of the patient; the tuberculin test is a skin test to determine whether the patient has active tuberculosis, but it can only be used as a screening test and not as a basis for diagnosis. The blood test is a more accurate way to determine the presence of Mycobacterium tuberculosis in the body, and then diagnose the presence of tuberculosis infection; 3. Imaging tests: Mycobacterium tuberculosis mostly attacks the lungs, and obvious lung lesions are common, so the diagnosis can be made by imaging tests such as chest X-ray and lung CT, and patients can see pathological changes in the lungs. In addition, TB is contagious and can be transmitted by droplets, so if there is a history of close contact with TB patients, early screening should be performed. If you are already infected, you should actively cooperate with treatment and also pay attention to meal sharing and wearing a mask when you go out to avoid infection until you are cured.