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Tuberculosis: What It Is and How It Affects the Body

Reviewed by
Date published
24/03/2021
Date last updated
25/02/2021
Length of read
5 Minutes

Tuberculosis (TB) is a bacterial infection spread by inhaling droplets from an infected person, either from them coughing or sneezing near you. TB affects the lungs primarily, but it can affect other parts of the body, such as the bones, glands and nervous system.

Tuberculosis can be incredibly serious but with the right treatment, it can be cured. So, what is tuberculosis, what are the symptoms and how does it affect your body?

Symptoms of Tuberculosis

There are several symptoms that sufferers of TB can develop, but the most common are:

  • A persistent cough which lasts for more than 3 weeks and involves bringing up phlegm that may contain blood
  • Weight loss
  • Night sweats
  • High temperature
  • Constant tiredness and fatigue
  • Loss of appetite
  • Swelling in the neck

If you have any of these symptoms, particularly a persistent cough or coughing up blood, then you should speak to your GP immediately.

How Tuberculosis affects the body

Tuberculosis is caused by a specific bacterium – M.tuberculosis. This virus spreads from person to person when the infected person coughs or sneezes out this bacterium and someone else breathes in the air, which is filled with these bacteria. It takes prolonged contact or exposure to someone who is infected with TB in order for you to develop it yourself, so if you’re spending time with a family member or a colleague, you’re more likely to develop it than from a casual acquaintance. However, once you breathe in the bacterium, it settles in your lung tissue and then develops.

You may find, if you’re someone who is generally healthy, that you contract latent TB which means that the disease may not present symptoms for several months or even years after you breathe it in. When your immune system becomes weak for any reason, this is when the symptoms will develop further. However, if you are someone with a weaker immune system or a pre-existing condition that leaves you more vulnerable to infections, you are at a greater risk of developing TB immediately.

When you breathe in the bacterium, it will settle in the lungs and begin to grow, due to the weakened immune system not being able to fight it off. TB can develop quickly in just a few days or weeks in this case. Active Tuberculosis means that the bacteria are multiplying quickly and attacking the lung tissue and other areas of the body, such as the kidneys, spine, bones, lymph nodes and even the skin. It moves through the blood and lymphatic system from the lungs.

What can cause Tuberculosis?

As a bacterial infection, TB that impacts the lungs is the most contagious form of the disease. This is known as pulmonary TB. However, it is usually contracted after spending long periods of time with someone who has the illness.

The body and immune system of a healthy person is usually capable of defending itself against TB and killing the bacteria, so there are no symptoms. In some cases, the body may not be able to kill the bacteria, but it is able to prevent it from spreading. This means that it will be present in the body, but you won’t have symptoms, which is known as latent TB. However, latent TB can become active if your immune system is weakened.

Can Tuberculosis be treated?

The good news is that with the right treatment, TB can almost always be cured but antibiotics will normally need to be taken for six months. There are several types of antibiotics needed to treat Tuberculosis, as some forms are resistant to certain types of treatment. If you are infected with a type of TB that is resistant to medications, you will require a course of several types of antibiotics for at least six months to clear the infection.

For those diagnosed with pulmonary TB, you will also be contagious for around two to three weeks, even when you’ve started treatment, so it’s important to be cautious and take precautions to prevent the risk of spreading it to those around you. This includes:

  • Staying home from work, school or university until your doctor has advised that it’s safe to return
  • Cover your mouth when coughing, sneezing or laughing
  • Dispose of used tissues in a sealed plastic bag
  • Open windows as much as possible to let fresh air into the areas where you’re spending the most amount of time
  • Don’t sleep in the same room as other people if possible

For those spending time with someone with TB, it’s important to get checked to see whether you’ve contracted the infection. These tests may include a blood test, a skin test (which is known as the Mantoux test) and a chest x-ray.