Kidneys can be damaged by tuberculosis. Tuberculosis generally affects the lungs, but may cause infection in many other organs in the body. (Image courtesy of the Centers for Disease Control and Prevention.)

Tuberculosis is caused by a group of organisms Mycobacterium tuberculosis, M. bovis, M. africanum and a few other rarer subtypes. Tuberculosis usually appears as a lung (pulmonary) infection. However, it may infect other organs in the body. Recently, antibiotic-resistant strains of tuberculosis have appeared. With increasing numbers of immunocompromised individuals with AIDS, and homeless people without medical care, tuberculosis is seen more frequently today. (Image courtesy of the Centers for Disease Control and Prevention.)

Tuberculosis is an infectious disease that causes inflammation, the formation of tubercules and other growths within tissue, and can cause tissue death. These chest x-rays show advanced pulmonary tuberculosis. There are multiple light areas (opacities) of varying size that run together (coalesce). Arrows indicate the location of cavities within these light areas. The x-ray on the left clearly shows that the opacities are located in the upper area of the lungs toward the back. The appearance is typical for chronic pulmonary tuberculosis but may also occur with chronic pulmonary histiocytosis and chronic pulmonary coccidioidomycosis. Pulmonary tuberculosis is making a comeback with new resistant strains that are difficult to treat. Pulmonary tuberculosis is the most common form of the disease, but other organs can be infected.

This x-ray shows a single lesion (pulmonary nodule) in the upper right lung (seen as a light area on the left side of the picture). The nodule has distinct borders (well-defined) and is uniform in density. Tuberculosis (TB) and other diseases can cause this type of lesion.

This CT scan shows a single lesion (pulmonary nodule) in the left lung. This nodule is seen as the light circle in the upper portion of the dark area on the left side of the picture. A normal lung would look completely black in a CT scan.

Miliary tuberculosis is characterized by a chronic, contagious bacterial infection caused by Mycobacterium tuberculosis that has spread to other organs of the body by the blood or lymph system.

Tuberculosis is a contagious bacterial disease that primarily involves the lungs. Tuberculosis may develop after inhaling infected droplets sprayed into the air from a cough or sneeze of someone infected with Mycobacterium tuberculosis.

This picture shows reddish-purple, hard (indurated), painful nodules (Erythema nodosum) that occur most commonly on the shins. These lesions may be anywhere on the body and may be associated with tuberculosis (TB), sarcoidosis, coccidioidomycosis, systemic lupus erythematosis (SLE), fungal infections, or in response to medications.

Air is breathed in through the nasal passageways, travels through the trachea and bronchi to the lungs.