Tuberculosis is caused by bacterium, Mycobacterium tuberculosis. It is a highly infectious disease. The bacterium affects the lungs, lymph nodes, bones and joints. The bacterium damages tissues and releases a toxin called tuberculin which produces the disease. Infection spreads by tiny droplets of sputum sprayed by the infected person by sneezing, coughing or spitting directly. Man may also get infection indirectly by taking contaminated milk of cow having bovine T.B. Symptoms of pulmonary (lungs) tuberculosis are fever, cough, blood containing sputum, pain in the chest and loss of weight, excessive fatigue, failure of appetite, slight rise of temperature in the evening, hoarseness of throat, night sweating and rapid pulse. Adequate rest, rehabilitation, diet and surgery are useful in controlling the diseases.