Tuberculosis (TB) Symptoms & Causes

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What is TB infection?

TB infection occurs if your child has a small number of TB germs in his body, but his immune system prevents the germs from causing any problems.

If your child has TB infection, usually he:

  • doesn’t feel sick
  • has a positive skin test reaction
  • can develop TB disease if he does not receive treatment for his TB infection

What is TB disease?

TB disease occurs when your child has a large number of TB germs living in his body and the germs are causing harm. Usually your child will feel sick, and he often can spread TB germs to others. TB disease can be found in any part of the body but it usually affects the lungs.

Common symptoms of TB disease are:

  • coughing
  • fever
  • loss of appetite
  • weight loss
  • weakness
  • night sweats
  • feeling very tired

If not treated properly, TB disease can be fatal. TB disease was once the leading cause of death in the United States.

Who is at risk for developing TB?

Your child is at risk for TB if he has ever had contact with a person who has had TB infection. Some groups of people who are at increased risk for TB include:

  • people born in less industrialized areas (Latin America, Asia, Africa)
  • medically underserved population usually in urban areas including children under the age of 4
  • homeless people
  • people who abuse alcohol
  • people who use intravenous drugs
  • the elderly
  • people in group settings, such as nursing homes
  • people with weak immune systems (especially those with HIV infection)
  • people with other medical risk factors such as diabetes and severe kidney disease

How is TB spread?

TB is spread from one person to another through the air. TB germs are launched into the air when a person with TB disease of the lungs coughs or sneezes.

TB in the lungs or throat can be spread to other people. TB in other parts of the body, such as the kidney or spine, is usually not infectious.

If your child has TB disease, he is most likely to spread it to people he spends time with every day, including family members and friends.

How does someone get infected with TB?

When someone with TB disease of the lungs coughs or sneezes near your child, your child can breathe in the TB germs and become infected. When this happens, the bacteria settle in your child’s lungs and begin to grow. From there, they can move through the blood to other parts of his body, such as the kidney, spine and brain.

What is BCG?

BCG is a vaccine for TB. This vaccine is not widely used in the United States, but it is often given to infants and small children in other countries where TB is common. BCG vaccine does not always protect people from getting TB.


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