What is tb?

Tuberculosis (TB) is a contagious infection that usually attacks the lungs, but can also spread to other parts of the body, such as the brain and spine. It is caused by a type of bacteria called Mycobacterium tuberculosis.

Here's a breakdown of key aspects of TB:

• Cause and Transmission: TB is caused by the bacteria Mycobacterium tuberculosis. It typically spreads through the air when a person with active TB disease of the lungs or throat coughs, sneezes, speaks, or sings. Close contact over a prolonged period is usually required for transmission. Find out more about transmission of TB.

• Types of TB: TB infection can exist in two forms:

  • Latent TB infection (LTBI): The bacteria live in the body but are inactive. People with LTBI don't feel sick, don't have symptoms, and can't spread the infection to others. However, LTBI can develop into active TB disease. Read more about latent TB infection.
  • Active TB disease: The bacteria are active and multiplying. People with active TB disease feel sick and can spread the infection to others. Understand more about active TB disease.

• Symptoms: Symptoms of active TB disease depend on where in the body the TB bacteria are growing. General symptoms can include:

  • 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

• Diagnosis: TB is usually diagnosed with a tuberculin skin test (TST) or a TB blood test. If these tests are positive, other tests, such as a chest x-ray and sputum samples, are needed to confirm active TB disease.

• Treatment: TB is treatable with antibiotics. Treatment for active TB disease typically involves taking several antibiotics for 6 to 9 months. It is very important to take the medicine exactly as prescribed by a healthcare provider. Treatment for LTBI is also available to prevent progression to active disease. Explore TB treatment options.

• Prevention: Preventive measures include:

  • Testing individuals at high risk for TB
  • Treating latent TB infection (LTBI)
  • Proper ventilation and infection control in healthcare settings.

• Risk Factors: Certain factors increase the risk of TB infection, including:

  • Close contact with someone with active TB disease
  • Weakened immune system (e.g., HIV infection, diabetes, certain medications)
  • Living or working in congregate settings (e.g., prisons, homeless shelters)
  • Travel to or residence in countries where TB is common.

• Global Impact: TB remains a major global health problem, particularly in developing countries. The World Health Organization (WHO) works to combat TB worldwide.