Symptoms and spread
Classic signs include a cough lasting three weeks or longer, coughing up blood, fever, night sweats, weight loss, and fatigue. TB spreads when someone with active lung disease coughs and others breathe in the bacteria. Most infected people develop latent TB infection: no symptoms, not contagious, but at risk of getting sick later.
Testing and treatment
A TB skin test or blood test (IGRA) checks for infection; chest X-rays and sputum tests diagnose active disease. Active TB takes several drugs for about six months, and skipping doses can breed drug-resistant TB. Treating latent TB with a 3–4 month regimen sharply cuts the risk of it turning active.
This article is general health information and is not a substitute for diagnosis or treatment. If symptoms persist, see a doctor.
FAQ
- Am I contagious with latent TB?
- No. People with latent TB have no symptoms and can't spread it.
- Does the BCG vaccine prevent TB?
- It protects young children from severe TB well, but its protection against adult lung TB is limited. It's rarely given in the U.S.
Sources reviewed: 2026-10-26
References
- World Health Organization. (2024). Global Tuberculosis Report 2024. WHO.
- Centers for Disease Control and Prevention. Clinical Overview of Latent Tuberculosis Infection. CDC.
- 질병관리청. (2024). 결핵 진료지침(제5판).