Active tuberculosis is tuberculosis that is active and requires treatment, as opposed to old tuberculosis. Old tuberculosis refers to fibrous tissue that remains after the tuberculosis has healed or been treated, and this scar tissue is usually inactive, i.e., free of bacteria, and does not require treatment. For active TB, once the diagnosis is clear, prompt anti-tuberculosis treatment is required. For primary tuberculosis, the general course of treatment is 6 months; for re-treated tuberculosis, the general course of treatment is 9 months. During the course of treatment, attention should be paid to observing the efficacy of the treatment, regularly reviewing the chest X-ray to determine the changes of the lung lesions, and paying attention to the adverse effects of anti-tuberculosis drugs.