What is Tuberculosis?

Tuberculosis (TB) is an infection that is caused by the Mycobacterium tuberculosis bacteria. It has the potential to be serious and mainly affects the lungs. In 2020, an estimated 10 million people fell ill with tuberculosis worldwide. Of these; 5.6 million were men, 3.3 million were women and 1.1 million were children. But TB is curable and preventable.

The infection spreads by a healthy person inhaling little droplets that come from an infected person, usually in the form of coughs and sneezes. Even though the lungs are the main organs affected, it can affect any part of the body (abdomen, glands, bones, etc.). However, not everyone who is infected becomes sick and TB can be split into two conditions named: latent TB infection (LTBI) and TB disease. The latter can be fatal if not treated properly. 

Tuberculosis is seen in every part of the world and mostly affects adults in their most productive years. Despite this, every age group is at risk. And, in terms of its distribution among the world countries, more than 95% of the cases and deaths are seen in developing countries. 

What are tuberculosis symptoms?

  • persistent cough lasting more than 3 weeks (usually with phlegm, and may be bloody)
  • weight loss
  • tiredness and fatigue
  • no appetite
  • night sweats
  • chest pain or feeling pain when breathing or coughing
  • fever

If TB disease is not in the lungs and is in another part of the body, symptoms would depend on the affected area. 

If the person has latent TB infection, they wouldn’t feel sick, wouldn’t show any symptoms and cannot spread TB to other people.

How is it diagnosed?

The most common tool used is a skin test, even though blood tests are becoming more prevalent. With a skin test a raised, red and hard bump means the result is likely positive for TB, and the size of it determines the significance of the result. But this test is not perfect, because there is the risk of false positives and false negatives. If a blood test is done, this can rule out or confirm both latent TB infection and TB disease. 

If the skin test is positive, the healthcare team may order a chest X-ray or a CT scan. If that also shows signs of tuberculosis, a sputum (the mucus that comes up when the patient coughs) test may be done.

How is tuberculosis treated?

For LTBI, only one or two types of TB drugs may be needed. These are the most common drugs:

  • Isoniazid
  • Rifampin 
  • Ethambutol 
  • Pyrazinamide

But if it is an active tuberculosis case, and particularly if it is a drug-resistant strain, it may require several drugs at once. Generally, a combination of antibiotics called fluoroquinolones and injectable medications, such as amikacin or capreomycin (Capastat), are used for 20 to 30 months.


  1. "Tuberculosis", United Kingdom National Health Service, 2019.
  2. "Tuberculosis - Symptoms & Causes, Diagnosis & Treatment", Mayo Clinic, 2021.
  3. "Tuberculosis", World Health Organization, 2021.
  4. "Tuberculosis (TB) - Signs & Symptoms", Centers for Disease Control and Prevention.

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