Tuberculosis can cause pleural effusion, which is a respiratory infectious disease caused by Mycobacterium tuberculosis infection of the lungs and is highly contagious. In addition to droplet transmission through the respiratory tract, it can also spread locally in the lungs through the airways, causing multiple cases of tuberculosis in the lungs. Also in immunocompromised individuals, such as those with diabetes, long-term hormone use, or HIV infection, TB bacteria can be transmitted to some extent through the bloodstream. Transmission to the bone marrow causes bone tuberculosis, transmission to the abdominal cavity causes tuberculous peritonitis, and transmission to the pleura can cause tuberculous pleurisy. When tuberculous pleurisy occurs, the pleura is continuously stimulated by the tuberculosis bacteria to produce pleural fluid, and pleural effusion can occur. Pleural effusion caused by pulmonary tuberculosis is essentially caused by the spread of tuberculosis to the pleura, which requires active treatment measures, and often requires thoracentesis to drain the pleural fluid along with anti-tuberculosis treatment.