{"output":"What is FEV1 Forced Expiratory Volume in 1 second?

Think of your lungs as a set of balloons that you squeeze to blow out birthday candles. FEV1 is simply a measurement of how much air you can forcefully blow out in just the first second of that big exhale.

Imagine holding a soft, inflated balloon. When you let it go, the air rushes out slowly and steadily. But when you pinch the neck and give it a hard squeeze, a burst of energy shoots out instantly. Forced Expiratory Volume in 1 second captures that initial, powerful burst. It tells doctors how fast your lungs can empty themselves after a deep breath.

If your airways are wide open, the air zips out like water from a garden hose on full blast. If they are tight or clogged, like trying to blow through a straw with melted ice cream inside, the air struggles and comes out slower. Doctors use this number to check for breathing problems like asthma or COPD.

A healthy person usually blows out most of their total lung capacity in that first second. A lower FEV1 suggests the lungs might be stiff or blocked, making it harder to breathe quickly. It is a simple, quick way to see if your "balloons" are working properly and getting rid of old air so fresh air can come in.