Pulmonary tuberculosis. Coloured lateral 3D computed tomography (CT) scan of the right lung of a patient with tuberculosis (TB), showing scarring and granuloma in the lung apex due to chronic pulmonary tuberculosis infection. The pleura have been digitally removed. TB is caused by infection with Mycobacterium tuberculosis bacteria. It is spread by the inhalation of droplets coughed or sneezed by an infected person. Symptoms of tuberculosis include blood-containing sputum, fever, night sweats and weight loss.