Patients who have not yet started anti-tuberculosis treatment, 2. Patients who have not completed a full course of regular treatment under the initial regimen, and 3. Patients who have not completed one month of irregular chemotherapy. Patients who have failed initial treatment, 2. patients with sputum reasserted after a full course of regular treatment, 3. patients with irregular chemotherapy for more than one month, and 4. patients with chronic persistent bacterial excretion. The definition of “primary” and “re-treatment” patients is important for guiding treatment: primary patients are mostly sensitive to anti-tuberculosis drugs, and the lesions are mostly exudative and reversible. We should seize the opportunity of initial treatment and apply anti-tuberculosis drugs reasonably. Patients who return to treatment are often resistant to anti-tuberculosis drugs, and the lesions are mostly irreversible, making treatment difficult. Another important significance of patients who return to treatment is that they are the main source of TB infection. The main task of both doctors and patients is to thoroughly treat primary TB patients and minimize their conversion to relapsed patients.