Tuberculosis (TB) is a common infection of the respiratory tract that remains endemic across much of the world. The causative pathogen, Mycobacterium tuberculosis, is transmitted from person to person by the airborne route and is therefore highly contagious. Not everyone infected with M. tuberculosis develops symptomatic illness. As a result, infections can be grouped into latent, or inactive TB or as active TB disease. For most individuals with active TB infection, the disease manifests as a chronic, indolent pneumonia associated with fever and weight loss. This symptom complex explains why active tuberculosis was once referred to as “consumption.” Unrecognized and untreated, the bacterial infection can spread to extrapulmonary sites including bones, joints, kidneys, and the brain. Disseminated disease occurs most commonly in young children and among adults with immunocompromising conditions or underlying chronic lung disease. Once diagnosed, treatment to achieve cure requires several months or longer of combination antimycobacterial therapy. Drug resistance to first-line therapeutic agents has increased in recent years, underscoring the importance of collecting quality samples for culture and prioritizing drug susceptibility testing on all isolates. The live, attenuated Bacillus Calmette-Guérin (BCG) vaccine used in many parts of the world is effective at preventing TB dissemination, particularly among young children who become infected, but the vaccine does not prevent infection itself.