Old tuberculosis is usually not cancerous. In patients with old tuberculosis, the lesions are usually in the state of calcification, and in the state of calcification, there is no local blood supply to the lesions, so there is no possibility of cancerous changes. As time passes, the calcified lesions may be gradually absorbed by the body, and after a long period of time, such as 10 years, the lesions may shrink or even disappear. Patients with old tuberculosis need to take appropriate physical exercise to strengthen their body and improve their resistance to avoid the recurrence of tuberculosis. They also need to rest well, not to stay up late, not to strain, and definitely not to smoke or drink. Patients with large foci of tuberculosis need to have regular annual chest CT examinations to monitor changes in the foci and regular sputum testing.