Pulmonary tuberculosis

Alternative Names

TB; Tuberculosis – pulmonary

Definition of Pulmonary tuberculosis

Pulmonary tuberculosis (TB) is a contagious bacterial infection that involves the lungs, but may spread to other organs.

Causes, incidence, and risk factors

Pulmonary tuberculosis (TB) is caused by the bacteria . You can get TB by breathing in air droplets from a cough or sneeze of an infected person. This is called primary TB.


The primary stage of TB usually doesn’t cause symptoms. When symptoms of pulmonary TB occur, they may include:

Signs and tests

Examination may show:


The goal of treatment is to cure the infection with drugs that fight the TB bacteria. Treatment of active pulmonary TB will always involve a combination of many drugs (usually four drugs). All of the drugs are continued until lab tests show which medicines work best.

Expectations (prognosis)

Symptoms often improve in 2 – 3 weeks. A chest x-ray will not show this improvement until later. The outlook is excellent if pulmonary TB is diagnosed early and treatment is begun quickly.


David C. Dugdale, III, MD, Professor of Medicine, Division of General Medicine, Department of Medicine, University of Washington School of Medicine; Jatin M. Vyas, MD, PhD, Assistant Professor in Medicine, Harvard Medical School, Assistant in Medicine, Division of Infectious Disease, Department of Medicine, Massachusetts General Hospital. Also reviewed by David Zieve, MD, MHA, Medical Director, A.D.A.M., Inc. – 12/7/2010

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ADAM Medical Encyclopedia

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