The most common cause is tuberculosis, which is accompanied by symptoms such as low fever, cough, night sweats, lethargy and weakness, and in severe cases, coughing up blood. Generally, anti-TB drugs are needed for active treatment, and the more commonly used drugs are rifampin, isoniazid, streptomycin and other drugs. There is also a case caused by cornified lung cancer, which can be diagnosed by pathological biopsy and imaging, and this is mainly treated by surgery.