Spirometry Interpretation: Normal Lung Function
Your spirometry results are completely normal and require no intervention or further testing. 1, 2
Primary Pattern Analysis
Your results show:
- FEV1/FVC ratio of 82% is well above the threshold for obstruction (>70% or above the 5th percentile), indicating normal airway caliber 1, 2
- FEV1 of 108% predicted is above normal (≥80% is normal), indicating excellent lung function 3, 2
- FVC of 109% predicted is above normal (≥80% is normal), indicating excellent lung capacity 1, 2
- PEF of 80% is within normal limits, though slightly lower than your volume parameters, which can occur with normal variation in effort 1
What This Means
- No obstructive pattern: Your FEV1/FVC ratio of 82% excludes COPD, asthma, or any other obstructive lung disease 3, 2
- No restrictive pattern: Both your FEV1 and FVC exceed 80% predicted and are proportionally normal, excluding restrictive lung disease 3, 1
- No mixed pattern: The combination of normal ratio and normal volumes rules out combined obstruction and restriction 3, 2
Clinical Implications
- No further testing needed: Lung volume measurements (TLC, RV) are not indicated when spirometry is entirely normal 1, 4
- No bronchodilator testing needed: With normal baseline spirometry, there is no indication for reversibility testing 2, 5
- Excellent prognosis: Normal spirometry is associated with standard population mortality and morbidity risks 6
Common Pitfalls to Avoid
- Don't over-interpret the PEF: A PEF of 80% with normal FEV1 (108%) and FVC (109%) represents normal variation and does not indicate disease 3, 1
- Don't pursue unnecessary testing: The negative predictive value of normal spirometry is >97% for excluding lung disease, making additional pulmonary function testing unnecessary in the absence of specific clinical concerns 4