This article, part of the "ATS/ERS Task Force: Standardization of Lung Function Testing" series, provides general considerations for lung function testing. It covers definitions, patient considerations, patient details, laboratory details, hygiene and infection control, personnel qualifications, technician's role in quality control, reference values, and interpretation strategies. Key points include: 1. **Definitions**: Accuracy, repeatability, and reproducibility are defined, emphasizing the importance of consistent measurement conditions. 2. **Patient Considerations**: Contraindications, positioning, and subject preparation are discussed, including the importance of avoiding certain activities before testing. 3. **Patient Details**: Age, height, weight, therapy, and subject preparation are detailed, with specific guidelines for each. 4. **Laboratory Details**: Environmental conditions, testing order, and the importance of accurate temperature measurements are highlighted. 5. **Hygiene and Infection Control**: Precautions to prevent infection transmission, including the use of in-line filters and proper equipment maintenance, are outlined. 6. **Personnel Qualifications**: Training requirements and the role of technicians in quality control are emphasized. 7. **Reference Values**: The selection of appropriate reference values and their sources is discussed. 8. **Interpretation Strategies**: The process of classifying derived values and integrating them into patient care is explained. The article aims to provide a comprehensive guide for both technical and clinical staff involved in lung function testing, ensuring standardized and reliable results.This article, part of the "ATS/ERS Task Force: Standardization of Lung Function Testing" series, provides general considerations for lung function testing. It covers definitions, patient considerations, patient details, laboratory details, hygiene and infection control, personnel qualifications, technician's role in quality control, reference values, and interpretation strategies. Key points include: 1. **Definitions**: Accuracy, repeatability, and reproducibility are defined, emphasizing the importance of consistent measurement conditions. 2. **Patient Considerations**: Contraindications, positioning, and subject preparation are discussed, including the importance of avoiding certain activities before testing. 3. **Patient Details**: Age, height, weight, therapy, and subject preparation are detailed, with specific guidelines for each. 4. **Laboratory Details**: Environmental conditions, testing order, and the importance of accurate temperature measurements are highlighted. 5. **Hygiene and Infection Control**: Precautions to prevent infection transmission, including the use of in-line filters and proper equipment maintenance, are outlined. 6. **Personnel Qualifications**: Training requirements and the role of technicians in quality control are emphasized. 7. **Reference Values**: The selection of appropriate reference values and their sources is discussed. 8. **Interpretation Strategies**: The process of classifying derived values and integrating them into patient care is explained. The article aims to provide a comprehensive guide for both technical and clinical staff involved in lung function testing, ensuring standardized and reliable results.