Tuberculosis is again the world’s deadliest infectious disease, yet it is preventable and curable. This guide explains how TB spreads, the signs to act on, how treatment works, and how to protect the people you live with.
Imagine your uncle has had a cough for six weeks. He blames the dust, the cold, the cigarettes. He has lost weight, sweats at night, and is too tired to work. The family buys cough syrup after cough syrup. When he finally has a sputum test, it shows TB, and three people in his household need to be checked too. Earlier testing could have spared them.
What is tuberculosis?
Tuberculosis (TB) is an infection caused by the bacterium Mycobacterium tuberculosis. It most often affects the lungs (pulmonary TB) but can affect almost any part of the body, including lymph nodes, bones, the spine, kidneys, brain and the lining of the heart or abdomen (extrapulmonary TB).,According to the WHO Global Tuberculosis Report, around 10.8 million people fell ill with TB in 2023 and about 1.25 million died, making TB once again the world’s leading cause of death from a single infectious agent. India, Indonesia, China, the Philippines, Pakistan, Nigeria, Bangladesh and the Democratic Republic of the Congo account for a large share of cases.
How TB spreads
TB spreads through the air when a person with active lung or throat TB coughs, sneezes, speaks or sings, releasing tiny droplets containing bacteria. People nearby can breathe them in. Prolonged close contact, such as living in the same home, sharing a bedroom or working in a crowded, poorly ventilated space, carries the highest risk.,TB is not spread by shaking hands, sharing food or drinks, touching bed linen or toilet seats, or kissing. TB outside the lungs is usually not infectious. Most people become non-infectious after about two weeks of effective treatment.
Latent TB vs active TB
When someone breathes in TB bacteria, the immune system often contains them without causing illness. This is called TB infection, or latent TB. People with latent TB have no symptoms, are not infectious, and have a normal chest X-ray, but the bacteria can become active later. An estimated quarter of the world’s population has been infected with TB.,About 5 to 10 percent of people with TB infection develop active TB disease during their lifetime, most often within the first two years. The risk is much higher in people with weakened immunity.
Who is at higher risk of active TB?
- People living with HIV, who are many times more likely to develop TB
- Young children, especially under five
- People with diabetes
- People who are undernourished
- People who smoke or drink heavily
- People on immunosuppressive treatment, including steroids and biologic drugs
- People with kidney failure or silicosis
- Household contacts of someone with TB
- People in prisons, shelters and crowded housing
- Healthcare workers
Symptoms of active lung TB
- A cough lasting more than two to three weeks
- Coughing up sputum or blood
- Fever, often in the evenings
- Night sweats that soak your clothes or bedding
- Unexplained weight loss and loss of appetite
- Tiredness and weakness
- Chest pain or breathlessness
Symptoms of TB elsewhere in the body
Symptoms depend on where TB is. Swollen, painless lymph nodes in the neck are common. Spinal TB can cause back pain and, if untreated, damage to the spine. TB meningitis causes headache, fever, neck stiffness, confusion and drowsiness, and is an emergency. Abdominal TB can cause pain, swelling and diarrhoea. General symptoms such as fever, weight loss and night sweats are often present too.
TB in children
Children often have less typical symptoms: a persistent cough, fever, not gaining weight or losing weight, reduced playfulness, or swollen glands. Babies and young children are more likely to develop severe forms such as TB meningitis. Any child in close contact with a person with TB should be assessed, even if well, and is usually offered preventive treatment.
How TB is diagnosed
WHO recommends rapid molecular tests, such as Xpert MTB/RIF Ultra or Truenat, as the first test for people with TB symptoms. These tests detect TB DNA in sputum within hours and also show whether the bacteria are resistant to rifampicin, a key drug. Sputum smear microscopy is still used in some places but misses many cases.,A chest X-ray helps detect lung TB and is used for screening, sometimes with computer-aided reading software. Culture of sputum takes weeks but is the most sensitive test and allows full drug susceptibility testing. For TB outside the lungs, samples from lymph nodes, fluid or tissue may be tested. In people with advanced HIV, a urine test (LF-LAM) can help diagnose TB quickly.
Giving a good sputum sample
- Take a deep breath, hold it, then cough hard from deep in your chest
- Spit the sputum (not saliva) into the container
- An early-morning sample is often best
- Do this outside or in a well-ventilated area, away from others
- Close the lid tightly and return it as instructed
Tests for latent TB
The tuberculin skin test (Mantoux) and interferon-gamma release assay (IGRA) blood tests show whether a person has been infected with TB, but cannot tell latent from active TB. They are used to screen contacts and people at higher risk before starting preventive treatment, once active TB has been ruled out. The BCG vaccine can cause false positive skin tests, which IGRA tests avoid.
Treatment of drug-sensitive TB
Standard treatment for drug-sensitive TB lasts six months. It begins with two months of four medicines (isoniazid, rifampicin, pyrazinamide and ethambutol), followed by four months of isoniazid and rifampicin. These are usually given as fixed-dose combination tablets, with the dose based on weight. Treatment is free in public programmes in most countries.,WHO also recommends shorter options for some people. A four-month regimen of rifapentine, isoniazid, pyrazinamide and moxifloxacin is an option for people aged 12 and over, and a four-month regimen is recommended for children with non-severe TB. Your TB team will choose the right option.
Why finishing treatment matters
Most people feel much better within a few weeks, but bacteria remain in the body. Stopping early can lead to relapse and to drug-resistant TB, which is much harder to treat. Take every dose for the full course, even if you feel completely well. Many programmes support treatment through community health workers, video-observed therapy, phone reminders or treatment supporters, an approach that replaces older strictly supervised (DOT) models with person-centred care.
Side effects to watch for
- Orange or red urine, tears and sweat from rifampicin (harmless, but it can stain contact lenses)
- Nausea or loss of appetite; taking tablets at bedtime may help
- Joint pain from pyrazinamide
- Tingling or numbness in hands and feet from isoniazid; vitamin B6 (pyridoxine) helps prevent it
- Changes in vision or colour vision from ethambutol: report immediately
- Yellow eyes or skin, dark urine, severe vomiting or abdominal pain, which may signal liver problems: stop and seek help urgently
- Skin rash, especially with fever
Drug interactions
Rifampicin speeds up the breakdown of many medicines, making them less effective. These include hormonal contraceptives, some HIV medicines, warfarin, some diabetes and epilepsy medicines, and methadone. Use a barrier or non-hormonal method of contraception during treatment and tell every healthcare provider and pharmacist that you are on TB treatment.
Drug-resistant TB
Multidrug-resistant TB (MDR-TB) does not respond to isoniazid and rifampicin, the two most powerful first-line drugs. Around 400,000 people develop MDR/rifampicin-resistant TB each year, and fewer than half are diagnosed and treated. Resistance develops when treatment is incomplete or inadequate, and resistant strains can also spread directly from person to person.,Treatment has improved dramatically. WHO now recommends a six-month, all-oral regimen called BPaLM (bedaquiline, pretomanid, linezolid and moxifloxacin) for most people aged 14 and over with MDR/RR-TB, replacing older regimens that lasted up to two years and involved painful injections with side effects such as deafness. Other all-oral regimens are used for children and in specific situations.
TB and HIV
TB is the leading cause of death among people living with HIV. Everyone with TB should be offered an HIV test, and everyone with HIV should be screened for TB at every visit. People with both infections should take treatment for both. ART is usually started within two weeks of starting TB treatment, except in TB meningitis, where timing is adjusted.,People living with HIV who do not have active TB should be offered TB preventive treatment, which significantly reduces their risk of developing TB disease.
TB and diabetes
Diabetes triples the risk of developing active TB, and TB can make blood sugar harder to control. People with TB should be screened for diabetes, and people with diabetes and symptoms such as a persistent cough should be tested for TB. Good blood sugar control improves TB treatment outcomes.
Preventive treatment for TB infection
Treating latent TB greatly reduces the risk of developing active disease. WHO recommends it for people with HIV, household contacts of people with lung TB (especially children under five), and other high-risk groups after active TB has been ruled out.,Options include three months of weekly rifapentine and isoniazid (3HP), one month of daily rifapentine and isoniazid (1HP), three or four months of rifampicin-based treatment, or six months of isoniazid. Shorter regimens are easier to complete. For contacts of people with MDR-TB, six months of levofloxacin is recommended in many cases.
The BCG vaccine
The BCG vaccine is given to babies at birth in countries with high TB rates. It protects young children well against severe forms such as TB meningitis and disseminated TB, but gives variable protection against lung TB in adults. Several new TB vaccines are in late-stage trials, including M72/AS01E, which could be the first new TB vaccine in a century if results are positive.
Infection control at home
- Open windows and doors to let fresh air circulate
- Cover your mouth and nose with a tissue or elbow when coughing or sneezing
- Wear a mask around others in the first weeks of treatment if advised
- Sleep in a separate room if possible until no longer infectious
- Avoid crowded places and public transport until your team says it is safe
- Ensure all household contacts are screened
Nutrition during treatment
TB and undernutrition feed each other. Eating enough energy and protein supports recovery and helps the body tolerate medicines. A trial in India (RATIONS) found that food support for families of people with TB reduced new cases among household contacts, and nutritional support for patients improved outcomes. Ask whether your programme offers food or financial support.
TB in pregnancy
TB in pregnancy needs prompt treatment, as untreated TB is far more dangerous to mother and baby than the medicines. First-line TB drugs are considered safe in pregnancy. Pyridoxine supplements are recommended. Breastfeeding is generally safe during treatment. Babies born to mothers with infectious TB may receive preventive treatment and BCG according to national guidelines.
Stigma, cost and getting help
Many people delay seeking care because of stigma or fear of losing work. TB is caused by a germ, not by a curse, poverty or poor character, and anyone can get it. Most countries provide TB testing and treatment free of charge, but families still face costs from travel, lost income and food. WHO estimates that about half of TB-affected households face catastrophic costs.,Ask your TB programme about social protection, transport support, and help to keep your job during treatment. Treatment supporters, peer groups and TB survivor networks can also help.
Life after TB
Many people recover completely, but some are left with lung damage, breathlessness or reduced lung function, known as post-TB lung disease. If you are still breathless or coughing after treatment, ask for a review. Pulmonary rehabilitation, vaccinations against flu and pneumococcus, and stopping smoking help protect your lungs. TB can occasionally return, so see a healthcare provider if symptoms come back.
When to get tested for TB
- A cough lasting more than two to three weeks
- Coughing up blood
- Night sweats, fever or unexplained weight loss
- Close contact with someone diagnosed with TB
- Living with HIV, even without symptoms (at every visit)
- Before starting biologic or immunosuppressive treatment
- A child who is not gaining weight and has been around someone with a cough
A short history of TB
TB has affected humans for thousands of years; evidence of it has been found in Egyptian mummies. In the 19th century it was known as consumption and caused a quarter of deaths in Europe. Robert Koch identified the bacterium in 1882, an anniversary now marked as World TB Day on 24 March.
The discovery of streptomycin in the 1940s, and later isoniazid and rifampicin, made TB curable. Rates fell sharply in wealthy countries, but TB surged again with the HIV epidemic and remains closely linked to poverty, crowding and undernutrition.
What happens at your TB clinic
At diagnosis, your nurse will explain the treatment plan, how to take the tablets, possible side effects, and how to protect others. You will usually be weighed, because doses depend on weight, and offered HIV and diabetes tests. A treatment card records each dose.
Follow-up visits check how you are feeling, your weight, side effects and how well you are taking the medicines. For lung TB, sputum is usually re-tested at the end of the intensive phase and at the end of treatment to confirm cure. Bring all your medicines and questions to each visit.
Contact tracing: protecting your family
When someone is diagnosed with infectious TB, the TB team will ask about household members and close contacts. They will be checked for symptoms and may have a chest X-ray, skin or blood test. Children under five and people with HIV who are contacts are usually offered preventive treatment even if their tests are negative. This is one of the most effective ways to stop TB spreading within families.
TB in healthcare and workplaces
- Screen staff for TB symptoms regularly and offer testing
- Triage coughing patients quickly and separate them in waiting areas
- Ensure good ventilation in clinics and wards
- Provide respirator masks (N95 or FFP2) for staff caring for patients with infectious TB
- Support staff who develop TB with paid leave and confidential care
Why TB is still common
TB thrives where people live in crowded, poorly ventilated housing, lack enough food, have limited access to healthcare, or live with HIV, diabetes or tobacco use. Ending TB requires not only medicines, but also better housing, nutrition, social protection and health systems. The world has committed to ending the TB epidemic by 2030 under the Sustainable Development Goals, but progress is off track.
Frequently asked questions
Is TB curable?
Yes. Most people with drug-sensitive TB are cured with six months of treatment, and new shorter regimens are curing most people with drug-resistant TB in six months.
How long am I infectious after starting treatment?
Most people with drug-sensitive TB are no longer infectious after about two weeks of effective treatment, but follow your team’s advice.
Can I drink alcohol during TB treatment?
It is best to avoid alcohol, because both alcohol and TB medicines can strain the liver.
Can TB come back?
Relapse is uncommon if the full course is completed, but it can happen. Reinfection is also possible in high-burden areas.
I had the BCG vaccine. Can I still get TB?
Yes. BCG protects children against severe TB but does not reliably prevent lung TB in adults.
Can my pets get TB from me?
Rarely. Some animals can get TB, but the main risk is to the people you live with.
But it is probably just a cough from the dust or the cold.
Most coughs are. But a cough that lasts more than two to three weeks, especially with weight loss, fever or night sweats, should be tested. A sputum test is simple and usually free. Finding TB early protects your lungs and the people you love.
Your next step: If you or someone at home has had a cough for more than two weeks, book a TB test at your nearest clinic this week.
Related: TB symptoms and testing · TB nursing care · Living well with HIV · Type 2 diabetes guide
Sources: World Health Organization (Global Tuberculosis Report 2024; consolidated TB guidelines), US Centers for Disease Control and Prevention, Stop TB Partnership, The Union.
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