Tuberculosis Definition.

What is Tuberculosis?

Tuberculosis (TB) is a life-threatening infection that primarily affects your lungs. Every year, tuberculosis kills nearly 2 million people worldwide. The infection is common — about one-third of the human population is infected with TB, with one new infection occurring every second.
Tuberculosis (TB) is a potentially fatal contagious disease that can affect almost any part of the body but is mainly an infection of the lungs. It is caused by a bacterial microorganism, the tubercle bacillus or Mycobacterium tuberculosis. Although TB can be treated, cured, and can be prevented if persons at risk take certain drugs, scientists have never come close to wiping it out. Few diseases have caused so much distressing illness for centuries and claimed so many lives.

Tuberculosis spreads through airborne droplets when a person with the infection coughs, talks or sneezes. In general, you need prolonged exposure to an infected person before becoming infected yourself. Even then, you may not develop symptoms of the disease. Or, symptoms may not show up until many years later.
Left untreated, tuberculosis can be fatal. With proper care, however, most cases of tuberculosis can be treated, even those resistant to the drugs commonly used against the disease.