Flow-Volume
Loop
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.com · flow vs volume · obstruction · restriction · airway collapse
pattern
normal
FEV1/FVC
0.80
read
baseline
shape
—
Normal loop (PEF apex, smooth limbs)
Obstruction: scooped / coved expiratory limb
Restriction: tall, narrow "witch's hat"
Plateau: fixed / variable airway obstruction
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.com · The Flow-Volume Loop: Reading Obstruction, Restriction, and Airway Collapse at a Glance