Old pulmonary tuberculosis is not contagious.

Inactive pulmonary tuberculosis is not contagious. Inactive pulmonary tuberculosis indicates that the patient previously had tuberculosis, which has since resolved and healed; however, residual lesions and scarring remain in the lungs—these findings are non-infectious. In certain circumstances—particularly when the patient has an underlying immunosuppressive disorder and requires high-dose corticosteroid therapy—the dormant tuberculous lesions may reactivate.