<unk>  can be classified into 6 main categories according to exposure, symptoms, and diagnostic testing. The classification ranges from Class 0, in people with no previous exposure to TB and negative tuberculin skin testing and/or interferon-gamma release assay (2 methods of screening for TB), to Class 3 for active TB infection and Class 5 for suspected TB infection based on signs and symptoms of the disease. The U.S. Citizenship and Immigration Services has also designed a special classification for immigrants and refugees according to the risk of infection.
Tuberculosis classification
Influenza classification
Pneumoconiosis classification
Kyphosis classification
Silicosis classification
Empyema classification
Hemoptysis classification
Aspiration pneumonia classification