Lung tuberculosis is an infection of the lungs which had been assumed to be wiped out in modern developed countries. However, there is again a rising number of cases. In addition, due tot he large number of refugees there are additional needs for characterising possible infections early. This is especially true as tuberculosis is still one oft he most often infectual diseases worldwide. X-ray imaging is at least for young patients not an easy to justify procedure. The gold standard for the diagnosis of tuberculosis is the cultural biology prove of Mycobacterium tuberculosis. This is quite a long and complicated procedure. It would be desirable to have a fast and easy diagnostic tool instead, because that could foster the in principle very effective therapy approaches, if applied in early stages. Since we know from earlier studies that breath gas analysis allows the detection of changes in the metabolism and especially those caused by infections we investigate the feasiblity to diagnose tuberculosis with breath gas analysis.