Tuberculosis

Tuberculosis (TB) is a contagious infectious disease caused mainly by Mycobacterium tuberculosis. It most commonly affects the lungs, but it can also involve lymph nodes, bones, kidneys, brain, and other organs. TB spreads through the air when a person with active pulmonary or throat TB coughs, sneezes, speaks, or sings.

TB infection may be latent or active. People with latent TB carry the bacteria without symptoms and cannot usually spread the infection. Active TB can cause persistent cough, chest pain, fever, night sweats, tiredness, weight loss, and sometimes coughing up blood. Symptoms may develop gradually, making early recognition important.

Diagnosis may involve medical history, physical examination, chest X-ray, sputum testing, molecular tests, and blood or skin tests for TB infection. Treatment depends on whether TB is latent or active and whether drug resistance is present. Active drug-sensitive TB is generally treated with a combination of antibiotics for several months. Completing the full treatment course is essential to prevent relapse and drug resistance.

Prevention includes early diagnosis and treatment, good ventilation, respiratory hygiene, contact screening, and appropriate preventive therapy for people at increased risk. Vaccination with Bacille Calmette-Guérin (BCG) is widely used in countries where TB is common, particularly to protect children from severe forms of disease.