Tuberculosis is an infectious disease caused by a bacterium known as mycobacterium tuberculosis. A German physician, Robert Koch in 1882, isolated this bacterium. Tuberculosis or most commonly known as TB affects the lungs but has the possibility of affecting any other organ. Earlier there was no cure for this disease and was considered to be fatal. Today, tuberculosis can be treated effectively with the help of antibiotics. A person is infected with TB if he/she inhales sputum particles from the air. The disease can spread when the person sneezes, coughs, shouts, or spits. Tuberculosis does not spread through touch or shaking hands. It spreads from person to person by breathing in the infected air. TB is also called as a transmitted disease.