Reduced forced vital capacity

What it means

An abnormal reduction in the amount of air a person can expel following maximal inspiration.

The threshold for an abnormally low FVC is defined as less than the LLN for adults or less than 80 percent of predicted for those five to 18 years of age, indicating a restrictive pattern. The LLLN (lower limit of normal) is a measurement less than the fifth percentile of spirometry data obtained from the Third National Health and Nutrition Examination Survey (NHANES III).

Rare diseases that can present with this7

The range is how often this sign appears among people diagnosed with each disease — it is not a probability of having any of them. Many of these signs also occur in common, non-rare conditions. A sign on this page is a conversation to have with a clinician, not a conclusion.

Part of the broader category

Also called: Decreased forced vital capacity · Reduced FVC