Tuberculosis is an infectious disease caused by Mycobacterium tuberculosis and less commonly by other organisms of 'tuberculosis complex'. The first evidence of tuberculosis was available long back in the skeletal remains from Neolithic era (9000-5000 B.C.) or tale/tale sign of Potts' disease in the Egyptian mummies (3700-1000 B.C.).In the ancient Chinese literature also this disease was described as 'consumption', 'Pthisis', 'white plague' etc. Tuberculosis typically affects the lungs (pulmonary TB) but can affect other sites as well (extra pulmonary TB). The disease is spread in the air when people who are sick with pulmonary TB expel bacteria, for example by coughing. In general, a relatively small proportion of people infected with Mycobacterium tuberculosis will go on to develop TB disease; however, the probability of developing TB is much higher among people infected with the human immunodeficiency virus (HIV). TB is also more common among men than women, and affects mostlyadults in the economically productive age groups; around two-thirds of cases are estimated to occur among people aged 15-59 years.