Tuberculosis (TB) is a contagious bacterial infection primarily affecting the lungs. Dr. Mayank highlights that TB is spread through airborne particles when an infected person coughs or sneezes. Symptoms include prolonged cough, chest pain, night sweats, and weight loss. It is treatable with a course of antibiotics, but the treatment duration can be lengthy. Early detection and treatment adherence are crucial to prevent drug-resistant strains. TB can be diagnosed through chest X-rays, sputum tests, and blood tests.