Tuberculosis (TB): symptoms, how it spreads and treatment

The NHS says symptoms usually come on gradually. Common ones are a cough lasting more than 3 weeks, which may bring up mucus or mucus with blood, feeling tired all the time, a high temperature or night sweats, loss of appetite, losing weight without trying and generally feeling unwell. Children may also have difficulty gaining weight or growing.

If TB has spread beyond the lungs the NHS says you may also have swollen glands, body aches, swollen joints, tummy or pelvic pain, constipation, dark or cloudy urine, headache, vomiting, confusion or irritability, or a rash. NHS inform lists gradually worsening breathlessness and new swellings or lumps that do not go away after a few weeks, and stresses that these symptoms have many causes and are not always a sign of TB.

NHS inform describes TB as a bacterial infection, caused by Mycobacterium tuberculosis, that mainly affects the lungs (pulmonary TB) but can affect any part of the body, including the glands, bones and nervous system (extrapulmonary TB). The NHS says it can be treated with antibiotics, can be serious if untreated, and that there is a vaccine for some people at risk.

The distinction between latent and active TB is central. The NHS explains that sometimes you can have TB in your body but no symptoms, which is called latent TB; if you have symptoms it is active TB. Latent TB cannot be spread to others but can turn into active TB in the future. NHS inform says that not everyone with TB is infectious, and people with TB outside the lungs generally do not spread the infection.

TB spreads when someone with active TB in the lungs coughs or sneezes and others inhale droplets containing the bacteria. The NHS says you can catch it by regularly breathing in these droplets over a long period, and NHS inform that it usually spreads after prolonged exposure, often within a household. NHS inform says that after about 2 weeks of treatment most people are no longer infectious and feel better, and you are contagious for up to 2 to 3 weeks into treatment, without usually needing isolation.

Practical steps from NHS inform include staying off work, school or college until the healthcare team says it is safe, covering your mouth with a disposable tissue and disposing of it in a sealed bag, opening windows, and not sleeping in the same room as others during that period.

The main treatment is antibiotics, usually for at least 6 months, according to the NHS. NHS inform says several different antibiotics are used and that drug-resistant TB needs additional medications and longer treatment. If TB has spread to the brain, spinal cord or the area around the heart, steroid medicine may be added for a few weeks. For latent TB the NHS says antibiotics are usually taken for 3 to 6 months, and NHS inform notes latent infection thought to be drug-resistant is not always treated but may be monitored.

Both sources stress completing the course even when you feel better. The NHS says that if you stop early, TB could come back, and NHS inform adds that skipping doses can let the infection become resistant. NHS inform says most people will not need hospital admission for treatment.

The NHS says antibiotics for active TB are usually taken for at least 6 months, and for latent TB for 3 to 6 months. NHS inform says drug-resistant TB needs additional medications and longer treatment.

NHS inform says that after about 2 weeks of treatment most people are no longer infectious and feel better, and that most people do not need hospital admission. Both sources stress completing the whole course even when you feel better: the NHS says TB could come back if you stop early, and NHS inform says skipping doses can let the infection become resistant.

The NHS says anyone can get TB but risk is higher for people who spend a lot of time with someone with active TB, were born in or lived where TB is more common, have a weakened immune system (HIV, diabetes, a kidney transplant, chemotherapy or biologic medicines), are under 5, are homeless, live in prison or a detention centre, regularly smoke, drink alcohol or take drugs, or have had TB before that was not treated properly.

Tests depend on the type. For active TB, the NHS lists an X-ray, ultrasound, echocardiogram or CT scan of the chest or the affected part of the body, tests on coughed-up mucus and a biopsy; NHS inform adds MRI and blood tests. A GP may refer you to a TB specialist for testing and treatment.

If you have no symptoms but are at risk, such as through close contact with someone who has TB, you may be offered a Mantoux skin test, in which a small amount of liquid is injected under the skin of the arm and causes a small reaction if you have TB infection, or blood tests. NHS inform says the interferon gamma release assay (IGRA) is a newer blood test that is becoming more widely available.

See a GP, says the NHS, if you have had a cough for more than 3 weeks, are tired for no reason, have a persistent fever or night sweats, poor appetite, unexplained weight loss, or have spent a lot of time with someone who has TB with symptoms, for example living with them. Ask for an urgent GP appointment or call NHS 111 if you are coughing up blood.

Call 999 or go to A&E for a stiff neck and severe headache, pain looking at bright lights, a seizure, sudden confusion or a change in behaviour, or weakness or loss of movement in part of the body, which could be signs of TB meningitis. Do not drive yourself to A&E.

The NHS says the BCG vaccine is recommended for some people at higher risk, including babies living in areas of the UK where TB is more common, babies and children who live with someone who has TB or who were born in or whose parents or grandparents were born in a country where TB is more common, people aged 35 and under who will spend more than 3 months in a country where TB is more common, and people at risk through work, such as healthcare workers who work with people who have TB.

GOV.UK explains that TB is a notifiable disease in the UK, meaning all suspected or confirmed cases must be reported to public health authorities within 3 working days. This supports contact tracing and screening of people who may have been exposed.

TB diagnosis, treatment and contact tracing in the UK are managed through NHS TB services working with public health teams. Because of notification duties and contact tracing, TB is not a condition that is handled privately in isolation.

A private GP or respiratory physician may arrange initial tests such as chest X-ray, IGRA or sputum samples, and should refer or notify appropriately if TB is suspected. If you are being screened for work, study or immigration reasons, confirm which tests the requesting organisation accepts.