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π©Ί Medically reviewed by the Health Decoded Guide Editorial Team · Last reviewed: August 2026
π Quick Summary
Tuberculosis (TB) is an infection caused by the bacterium Mycobacterium tuberculosis. It most commonly affects the lungs but can also affect other parts of the body.
TB is preventable and curable. However, untreated active TB can become serious and can spread to other people, making early diagnosis and completing treatment especially important.
1οΈβ£ Introduction
Tuberculosis is an infectious disease that mainly spreads through the air.
A person with active TB affecting the lungs or throat can release bacteria into the air when they cough, speak or sing.
• TB most commonly affects the lungs
• some people carry TB bacteria without feeling sick
• active TB usually requires several months of antibiotic treatment
π TB is a serious infection, but with proper diagnosis and treatment, most people can recover.
2οΈβ£ How it happens
TB bacteria can enter the body when a person breathes in contaminated airborne particles.
After reaching the lungs:
• the immune system may successfully contain the bacteria
• the bacteria may remain inactive for years
• if immune control weakens, the bacteria can multiply and cause active disease
π Someone can carry TB bacteria without having symptoms or being infectious.
3οΈβ£ Types
Latent TB infection
• TB bacteria are present but inactive
• the person has no symptoms
• the person cannot spread TB to others
• treatment may be recommended to prevent active disease
Active TB disease
• bacteria are multiplying and causing illness
• symptoms may develop
• pulmonary or throat TB may spread to other people
π Latent TB infection and active TB disease are not the same thing.
4οΈβ£ Common causes and risk factors
Exposure
• prolonged close contact with someone who has infectious TB
• living or working in settings where TB transmission is more likely
Higher risk of active disease
• weakened immune system, including from HIV
• malnutrition
• diabetes
• smoking
• very young or older age
• medicines or conditions that suppress the immune system
π Anyone can develop TB, but certain health and living circumstances increase the risk.
5οΈβ£ Symptoms
Active TB affecting the lungs may cause:
• persistent cough, often lasting 3 weeks or longer
• coughing up blood or sputum
• chest pain
• fever
• night sweats
• unexplained weight loss
• reduced appetite
• persistent tiredness
π TB symptoms often develop gradually, which can make the infection easy to overlook at first.
6οΈβ£ Associated symptoms or complications
TB can sometimes spread beyond the lungs and affect areas such as:
• lymph nodes
• bones and joints
• kidneys
• abdomen
• brain and its surrounding tissues
Serious complications may include meningitis, severe lung damage or widespread TB infection.
π Symptoms outside the lungs vary depending on which part of the body is affected.
7οΈβ£ π©Ί When it becomes dangerous π¨
Seek prompt or urgent medical care for:
• coughing up significant amounts of blood
• severe difficulty breathing
• severe chest pain
• confusion or reduced consciousness
• severe headache with neck stiffness
• persistent cough with_
π These may indicate:
• severe or complicated active TB or another serious illness
• need for urgent medical assessment
8οΈβ£ Management / treatment
Active TB is treated with a combination of antibiotics, usually taken for several months.
Management may include:
• taking several anti-TB medicines together
• completing the entire treatment course
• regular medical monitoring
• testing and assessment of close contacts
• measures to reduce transmission while the person remains infectious
π Stopping TB medicines too early can allow the infection to return and contribute to drug-resistant TB.
9οΈβ£ Diagnosis
TB investigation may involve:
• medical history and physical examination
• chest X-ray
• sputum testing
• molecular tests for TB bacteria and drug resistance
• skin or blood testing for TB infection
π No single test answers every TB question—the tests needed depend on whether doctors are investigating infection or active disease.
π’ Important Message
Tuberculosis is curable.
Early diagnosis protects both the person with TB and the people around them, while completing treatment helps prevent recurrence and drug resistance.
π If you have a persistent cough, especially with night sweats, fever or unexplained weight loss, get medically assessed rather than waiting for it to disappear.
FAQ
• Is tuberculosis contagious?
Active TB affecting the lungs or throat can spread through the air. Latent TB infection does not spread from person to person.
• Can TB be cured completely?
Yes. Most drug-susceptible TB can be cured when the correct medicines are taken for the full recommended treatment period.
• Can you get TB more than once?
Yes. A person can develop TB again after previous treatment through recurrence or a new infection.
• Is there a vaccine against TB?
Yes. The BCG vaccine is used in many countries and provides important protection against severe forms of TB in young children, although protection against pulmonary TB in adults is variable.
π§ Why We Delay
TB often starts gradually, so a persistent cough, tiredness or weight loss may initially be blamed on a common respiratory infection, stress or poor appetite. Fear of stigma can also make some people hide symptoms or avoid testing.
Delaying assessment allows active TB to become more serious and, when the disease is infectious, gives it more opportunity to spread to others. TB can be treated successfully, and seeking care early benefits both the individual and the community.
π TB is an infection—not something to be ashamed of. Testing and completing treatment are the steps that stop its spread.
π Related Health Topics
• Persistent Cough in Children
• Chest pain
• Pneumonia
• HIV
• Unexplained Weight Loss
π Medical References
• World Health Organization (WHO). Tuberculosis.
• Centers for Disease Control and Prevention (CDC). Tuberculosis (TB).
• National Health Service (NHS). Tuberculosis (TB).
• Mayo Clinic. Tuberculosis.
• National Institute for Health and Care Excellence (NICE). Tuberculosis.
β οΈ Medical Disclaimer
This article is for educational purposes only and does not replace professional medical advice.
If you have concerning symptoms, risk factors or abnormal test results, consult a healthcare professional.