Tuberculosis (TB) infection usually occurs initially in the lungs (Pulmonary).

Tuberculosis (TB) infection usually occurs initially in the lungs (Pulmonary). The body immune system, however, can stop the bacteria from continuing to reproduce. Thus, the immune system can make the lung infection inactive (dormant). On the other hand, if the body immune system cannot contain the TB bacteria, the bacteria will reproduce (become active or reactivate) in the lungs and spread elsewhere in the body(Extra-Pulmonary). It may take many months from the time the infection initially gets into the lungs until symptoms develop. The usual symptoms that may occur with an active TB infection are a generalized tiredness or weakness, weight loss, fever, and night sweats. If the infection in the lung worsens, then further symptoms can include coughing (more than 2 weeks), chest pain, coughing up of sputum (material from the lungs) and/or blood, and shortness of breath. If the infection spreads beyond the lungs, the symptoms will depend upon the organs involved.

Risk Factors

• HIV infection (the virus that causes AIDS)
• Substance abuse
• Silicosis
• Diabetes mellitus
• Severe kidney disease
• Low body weight
• Organ transplants
• Head and neck cancer
• Medical treatments such as corticosteroids or organ transplant
• Specialized treatment for rheumatoid arthritis or Crohn’s disease

How TB Spreads

TB is spread through the air from one person to another. The TB bacteria are put into the air when a person with TB disease of the lungs or throat coughs, sneezes, speaks, or sings. People nearby may breathe in these bacteria and become infected.

Symptoms of TB disease depend on where in the body the TB bacteria are growing. TB bacteria usually grow in the lungs (pulmonary TB). TB disease in the lungs may cause symptoms such as

• a bad cough that lasts 3 weeks or longer
• pain in the chest
• coughing up blood or sputum (phlegm from deep inside the lungs)
• weakness or fatigue
• weight loss
• no appetite
• chills
• fever
• sweating at night