how is tuberculosis caused
What Causes TB. Tuberculosis is an infection caused by bacteria. It's spread through the airâwhen an infected person coughs, sneezes, laughs, etc. However, it is not easy to become infected with tuberculosis. Usually a person has to be close to someone with TB disease for a long period of time.
1 A bacterium, Mycobacterium tuberculosis, causes the disease.  There are many risk factors for TB. Clinical symptoms and signs of pulmonary TB include fever, night sweats, cough, hemoptysis (coughing up blood-stained sputum), weight loss, fatigue, and chest pain.