Tuberculosis is caused by rod-shaped bacteria of the genus Mycobacterium tuberculosis. These are small, highly resistant pathogens that can be inhaled. In this way, the bacteria enter the lungs, where they are usually controlled or encapsulated by the body's own immune system. Nevertheless, the tuberculosis bacteria can survive there in a kind of dormant state. This state is known as latent tuberculous infection (LTBI). These people are not ill, and in some cases the infection heals. In 5-10% of cases, however, the immune system is unable to control the infection and the bacteria can multiply. As the body recognizes and wants to eliminate them, an inflammatory reaction occurs. If this progresses, it leads to tuberculosis, which then causes complaints or symptoms.