Tuberculosis, often called TB, is a contagious bacterial infection primarily affecting the lungs. It is caused by the bacterium Mycobacterium tuberculosis, which spreads through the air when an infected person coughs or sneezes. Symptoms include a persistent cough, chest pain, fever, and weight loss. While it can be serious, many people can recover with proper treatment. Treatment for TB usually involves a long course of antibiotics, often lasting six months or more. It's essential to complete the full treatment to prevent the bacteria from becoming resistant to medications. Vaccines, like the BCG vaccine, can help protect against severe forms of the disease, especially in children.