Active TB is progressive or improving TB, and patients with this disease need treatment.
In contrast, old TB, also known as inactive TB, is diagnosed as inactive TB when there are no clinical signs and symptoms associated with active TB, bacteriological tests are negative, imaging is consistent with the manifestations of inactive TB, and changes in lung imaging due to other causes are excluded. Patients do not require special management but should be monitored regularly as the lesion can become active TB if the body is resistant.