Forced Expiratory Volume in 1 Second (FEV1)
- Sample Type
- Standard
- Fasting
- No
- Unit
- Liters
FEV1 is the volume of air that can be forcibly exhaled from the lungs in the first second of a forced expiratory maneuver. It is the most critical parameter in Pulmonary Function Testing for identifying obstructive lung diseases. It measures how quickly the lungs can be emptied, which is directly impacted by airway resistance and lung recoil.
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Enter your lab result to see where you stand compared to the standard reference range.
Why Context Matters
FEV1 results are highly dependent on patient effort and technique. Poor coaching or patient exhaustion can lead to falsely low readings. Results must also be interpreted relative to 'Predicted' values based on height, age, gender, and ethnicity.
Lab ranges are statistical averages, not biological laws. "Normal" for a 20-year-old male isn't normal for a 60-year-old female.
Clinical References
Source-of-truth databases and clinical guidelines for Forced Expiratory Volume in 1 Second (FEV1):
Official Sources
- GOLD 2024: a brief overview of key changes - PMCpmc.ncbi.nlm.nih.gov
Research & Guidelines
Related Indicators
Medically Reviewed by Dr. Binoy Babu, MBBS
Board Certified Doctor • 10+ Years Clinical Experience
Dr. Babu is a practicing physician dedicated to empowering patients with clear, actionable medical information. He founded 2opi to bridge the gap between complex lab reports and patient understanding, ensuring everyone has access to a reliable second opinion.
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