Tuberculosis (TB) is a contagious bacterial infection caused by the bacterium Mycobacterium tuberculosis. It primarily affects the lungs but can also impact other parts of the body. TB spreads through the air when an infected person coughs or sneezes, releasing tiny droplets containing the bacteria. Symptoms of TB include a persistent cough, chest pain, weight loss, fever, and night sweats. Diagnosis typically involves a skin test or blood test, followed by chest X-rays. Treatment usually requires a long course of antibiotics, often lasting six months or more, to effectively eliminate the bacteria and prevent the spread of the disease.