Finding Mycobacterium tuberculosis in sputum smear is the most accurate way to diagnose tuberculosis. The test has high specificity but low sensitivity, and most of the patients with tuberculosis have negative sputum smear results. Therefore, sputum smear has limited application and it is difficult to diagnose tuberculosis only by sputum smear examination in clinic. The diagnosis of tuberculosis should be combined with the patient’s symptoms and auxiliary examinations. Patients with tuberculosis often have symptoms such as coughing, coughing up sputum, low-grade fever, fatigue, night sweats (abnormal sweating after going to sleep, but sweating stops after waking up), and weight loss, etc. With the above symptoms, combined with auxiliary examinations such as tuberculin test, chest X-ray, and gamma-interferon release assay, the diagnosis of tuberculosis can be made initially, and anti-tuberculosis treatment can be carried out. When symptoms of suspected tuberculosis appear, patients should seek medical treatment in time to complete the examination and follow the doctor’s instructions to carry out the appropriate treatment after a clear diagnosis.