Tuberculosis Basics: A Beginner-Friendly Start

A bacterial infection that usually affects the lungs and can stay inactive in the body (latent TB infection) or cause illness (TB disease).

Key takeaways

• How it spreads: through the air when someone with TB disease of the lungs or throat coughs, speaks or sings
• Latent TB infection: no symptoms and not contagious, but can become TB disease later
• Most useful single change: Ask your doctor about TB testing if you were born in or lived in a country where TB is common, live or work in a shelter or correctional facility, or have been near someone with TB disease.
• Commonest mistake: Stopping treatment early, which can lead to drug-resistant TB.
• See a doctor if any of the signs under "When to speak to a doctor" below apply to you.

Why bother

Treating latent infection prevents it from turning into TB disease later, and TB disease can be cured with a full course of medicine.

Start here

Two things, and nothing else until both feel routine.

• Ask your doctor about TB testing if you were born in or lived in a country where TB is common, live or work in a shelter or correctional facility, or have been near someone with TB disease
• Tell your doctor if you have HIV, diabetes, or take medicines that weaken the immune system, since these raise the risk of TB disease

Then add these

Once the first two are automatic, these are worth adding.

• Take every dose of TB treatment; ask about directly observed therapy or video check-ins if that helps
• Follow your health department's advice about staying home while contagious

The numbers, in one place

Common early mistakes

• Stopping treatment early, which can lead to drug-resistant TB
• Assuming a positive test always means you can spread TB; latent infection is not contagious
• Ignoring a long-lasting cough because it is not painful

Related topics

• The Evidence on Antibiotics, Without the Hype (Immunity)
• Persistent Cough: What the Evidence Actually Says (Respiratory Health)
• Shingles Vaccination: What the Evidence Actually Says (Vaccinations)
• Hepatitis B and C: What the Evidence Actually Says (Liver Health)

Where to go next

• Understanding Tuberculosis Basics: A Plain-English Explainer
• Tuberculosis Basics: The Practical To-Do List
• Tuberculosis Basics — the reference entry
• Infectious Diseases: The Complete Guide
• RSV (Respiratory Syncytial Virus): Sorting the Evidence From the Noise
• COVID-19: What the Evidence Actually Says

When to speak to a doctor

See your doctor for a cough lasting 3 weeks or more, coughing up blood, chest pain, night sweats, fever or unexplained weight loss. Call 911 for coughing up large amounts of blood or severe trouble breathing.

Where this comes from

• CDC — About Tuberculosis
• US Preventive Services Task Force — Latent Tuberculosis Infection in Adults: Screening

How this page was put together

Every figure, recommendation and warning above is taken from the guidance named in Where this comes from. Nothing on this page is inferred, summarized or generalized beyond what those bodies publish: where they give a number, it is their number, and where they are silent, so are we. Pages are rebuilt whenever the underlying record changes. Sign-off by a named clinician, where it has happened, is shown at the top of the page along with the date.

Medical disclaimer

This article is general information, not medical advice. It cannot account for your own history, medication or circumstances. Always speak to your doctor, pharmacist or another qualified health professional before making changes that affect your treatment, and never delay seeking medical advice because of something you have read here. In an emergency, call 911.