Lung Function Test

A normal lung function result is typically 80% or above of the predicted value for your age, height, sex, and ethnicity. Values between 70–79% may indicate mild impairment, while below 70% can suggest moderate to severe lung disease.

FEV1 (Forced Expiratory Volume in 1 second) is the amount of air you can forcefully exhale in one second. It is one of the most important measures of lung health. A low FEV1 can indicate obstructive lung conditions such as asthma or COPD.

Reduced lung function can be caused by smoking, chronic obstructive pulmonary disease (COPD), asthma, pulmonary fibrosis, respiratory infections, air pollution exposure, obesity, and aging. Some causes are reversible with treatment, while others cause permanent decline.

Yes, in many cases lung function can be improved or maintained. Quitting smoking, regular aerobic exercise, pulmonary rehabilitation, treating underlying conditions like asthma, and avoiding air pollutants can all help improve or preserve lung capacity.

FVC (Forced Vital Capacity) is the total amount of air you can forcibly exhale after taking a deep breath. FEV1 is how much of that air you exhale in the first second. The FEV1/FVC ratio helps doctors distinguish between obstructive and restrictive lung conditions.

A spirometry test is the most common lung function test. You breathe into a mouthpiece connected to a spirometer. You will be asked to inhale deeply and then exhale as fast and as hard as possible. The test usually takes 15–30 minutes and is painless.

Lung function typically peaks in your mid-20s and naturally begins to decline from around age 30 onwards. The rate of decline accelerates with age, and is faster in people who smoke, have lung disease, or are exposed to air pollutants.

Peak flow is a measurement of how fast you can blow air out of your lungs. It is commonly used to monitor asthma. A personal best peak flow reading is compared to current readings to assess asthma control. Low peak flow can signal an asthma attack or flare-up.

Yes, COVID-19 can affect lung function, particularly in people who had severe illness. Some people experience long-term breathing difficulties, reduced exercise tolerance, and lower lung capacity as part of Long COVID. Pulmonary rehabilitation can help recovery.