Tuberculosis (TB)

Tuberculosis (TB) is a bacterial infection spread through inhaling tiny droplets from the coughs or sneezes of an infected person.

It mainly affects the lungs, but it can affect any part of the body, including the tummy (abdomen), glands, bones and nervous system.

TB is a potentially serious condition, but it can be cured if it's treated with the right antibiotics.

Symptoms of TB

Typical symptoms of TB include:

• a persistent cough that lasts more than 3 weeks and usually brings up phlegm, which may be bloody
• weight loss
• night sweats
• high temperature
• tiredness and fatigue
• loss of appetite
• swellings in the neck

You should see a GP if you have a cough that lasts more than 3 weeks or you cough up blood.

Read more about the symptoms of TB and diagnosing TB.

What causes TB?

TB is a bacterial infection. TB that affects the lungs (pulmonary TB) is the most contagious type, but it usually only spreads after prolonged exposure to someone with the illness. 

In most healthy people, the body's natural defence against infection and illness (the immune system) kills the bacteria and there are no symptoms.

Sometimes the immune system cannot kill the bacteria, but manages to prevent it spreading in the body.

You will not have any symptoms, but the bacteria will remain in your body. This is known as latent TB. People with latent TB are not infectious to others.

If the immune system fails to kill or contain the infection, it can spread within the lungs or other parts of the body and symptoms will develop within a few weeks or months. This is known as active TB.

Latent TB could develop into an active TB disease at a later date, particularly if your immune system becomes weakened.

Read more about the causes of TB

Treating TB

With treatment, TB can almost always be cured. A course of antibiotics will usually need to be taken for 6 months.

Several different antibiotics are used because some forms of TB are resistant to certain antibiotics.

If you're infected with a drug-resistant form of TB, treatment with 6 or more different medications may be needed.

If you're diagnosed with pulmonary TB, you'll be contagious for about 2 to 3 weeks into your course of treatment.

You will not usually need to be isolated during this time, but it's important to take some basic precautions to stop the infection spreading to your family and friends.

You should:

• stay away from work, school or college until your TB treatment team advises you it's safe to return
• always cover your mouth when coughing, sneezing or laughing
• carefully dispose of any used tissues in a sealed plastic bag
• open windows when possible to ensure a good supply of fresh air in the areas where you spend time
• avoid sleeping in the same room as other people 

If you're in close contact with someone who has TB, you may have tests to see whether you're also infected. These can include a chest X-ray, blood tests, and a skin test called the Mantoux test.

Read more about treating TB

Vaccination for TB

The BCG vaccine offers protection against TB, and is recommended on the NHS for babies, children and adults under the age of 35 who are considered to be at risk of catching TB.

The BCG vaccine is not routinely given to anyone over the age of 35 as there's no evidence that it works for people in this age group.

At-risk groups include:

• children living in areas with high rates of TB
• people with close family members from countries with high TB rates
• people going to live and work with local people for more than 3 months in an area with high rates of TB

If you're a healthcare worker or NHS employee and you come into contact with patients or clinical specimens, you should also have a TB vaccination, irrespective of age, if:

• you have not been previously vaccinated (you do not have a BCG scar or the relevant documentation), and
• the results of a Mantoux skin test or a TB interferon gamma release assay (IGRA) blood test are negative

Read more about who should have the BCG vaccine

Countries with high TB rates

Parts of the world with high rates of TB include:

• Africa – particularly sub-Saharan Africa (all the African countries south of the Sahara desert) and west Africa
• south Asia – including India, Pakistan, Indonesia and Bangladesh
• Russia
• China
• South America
• the western Pacific region (to the west of the Pacific Ocean) – including Vietnam, Cambodia and the Philippines 

GOV.UK has detailed information on each country's TB rates

Page last reviewed: Sat Nov 2022 Next review due: Sat Nov 2022