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What Is Tuberculosis?

Tuberculosis (TB) is an infection caused by a type of bacteria that attacks and destroys body tissues. It usually affects lungs but can also spread (disseminate) to bones, lymph glands (nodes), nervous system, heart, and other organs.

Many people first have inactive TB, called a latent infection. Later TB becomes active, especially if the immune (infection-fighting) system is weakened, such as by HIV, cancer, or chemotherapy.

What Causes TB?

The cause is a type of bacteria named Mycobacterium tuberculosis. People catch TB by close contact, such as breathing in bacteria in the air that someone spread by coughing.

What Are the Symptoms of TB?

People in early stages often feel normal. Symptoms vary depending on which organs are affected and may include a cough lasting at least 3 weeks, coughing up sputum (phlegm) or blood, chest pain, fever, night sweats, losing weight and appetite, tiredness, and weakness.

How Is TB Diagnosed?

The health care provider will suspect TB in people with an unexplained cough, weight loss, or fever. The health care provider will ask about contact with places and people, history of TB or skin test results, risk factors (especially HIV), foreign travel, and job exposure. A tuberculin skin test (PPD) may be done. For this test, a tiny amount of fluid containing protein derived from TB bacteria is injected under the skin on the arm and swelling that appears is measured 48 to 72 hours later. The size of swelling (induration) where the fluid was injected determines if the tuberculin test is positive. A positive test usually means that the person has been exposed to TB. A blood test called QuantiFERON (QFT-6) can also be done to screen for exposure to TB.

If the PPD test or the QuantiFERON test is positive, the health care provider may also want to take chest x-rays and samples of sputum, blood, or urine to look for the presence of mycobaceria. A test for HIV may also be done.

How Is TB Treated?

Active TB can nearly always be cured, usually by taking medicines for 6 months or longer. Appropriate treatment usually requires a regimen of 3 to 4 antibiotics taken daily. People should feel better after a few weeks. It’s very important to finish the treatment, even if symptoms disappear. If medicines are stopped too soon, bacteria may stay in the body, and TB may return and spread to other parts of the body and to others. Family members and close contacts will need TB screening.

DOs and DON’Ts in Managing TB:

  • DO take your medicines exactly as your health care provider tells you.
  • DO use a routine, such as a pill dispenser, that helps you remember to take your medicines.
  • DO ask your health care provider about medicine side effects.
  • DO keep follow-up health care provider appointments.
  • DO be careful not to infect others. Follow your health care provider’s advice on hygiene.
  • DO call your health care provider if you have fever or chills, concerns about effects of medicines, or lasting or worsening symptoms despite taking medicines, or if you cough up discolored sputum or blood.
  • DON’T stop treatment early.
  • DON’T smoke.
  • DON’T assume you’re not infective unless your health care provider says so.
  • DON’T drink alcohol or take other medicine unless you talk with your health care provider first. Alcohol is toxic to the liver and may interfere with medications you are taking for TB.

Contact the following sources:

  • Centers for Disease Control and Prevention
    Tel: (800) 232-4636
  • The American Lung Association
    Tel: (800) 548-8252

Copyright © 2016 by Saunders, an imprint of Elsevier, Inc.

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