Tuberculosis
Tuberculosis, or TB, is a bacterial infection that most often affects the lungs but can involve other organs. Many infected people have latent TB: the bacteria remain inactive, without symptoms or the ability to infect others. Some later develop active disease. Babies and people with weakened immune systems are at greater risk of progressing to illness.
Prevention: Mixed
Symptoms
- A prolonged cough, sometimes with blood
- Fever and night sweats
- Poor appetite and weight loss
- Latent infection causes no symptoms
Transmission
- Breathing in bacteria released into the air by someone with contagious TB of the lungs or airways
Prevention
Avoid prolonged exposure to untreated contagious TB. People working in high-risk settings may need respiratory protection and testing. Ask a healthcare professional about appropriate precautions before an extended stay or healthcare work in an area with frequent TB.
Where it occurs
TB occurs worldwide, with large differences in frequency between communities and regions.
Diagnosis and care
Tests help distinguish infection from active disease. TB can be treated with a combination of medicines, and latent infection can also be treated to prevent disease. Completing the prescribed treatment is important.
Source
- Tuberculosis
Based on CDC information
Source language: English
Source reviewed: April 23, 2025
Source accessed: May 17, 2026
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