Tuberculosis is caused by the bacterium Mycobacterium tuberculosis and is a problem in San Bernardino and worldwide. It can easily spread from person to person through the air and remain infectious for hours. TB is diagnosed through chest x-rays, skin tests, and treated with antibiotics. In the early 1900s, San Bernardino County saw over 3,000 TB-related deaths in a single year due to immigrants seeking treatment. Controlling TB remains an issue as undocumented immigrants may be sick but lack healthcare or live in poor conditions, enabling the spread of the disease. Preventative measures through testing, regulations, and cooperation between groups are the best ways to stop the spread of TB.