So, you (pay to?) see a specialist.. then ask on here, when, with no disrespect to anyone, posters are often given unreliable replies?
Why not ask the specialist?
Fev1/FVC is your measure that is important and 75% ratio is in the normal range - at worst mild copd, possibly late onset asthma (hence O2's question regarding reversibility) or just unfit and/or obese.
However that assumption/calculation is based on an fairly low FVC (lung capacity) for people posting on here.
Fev1 (Forced Expiry Volume) is the volume of air that you can blow out in 1 second.
FVC (Forced vital capacity) is your lung capacity, the total volume of air that can forcibly be blown out after full inspiration in however long, but usually stopped at 12 seconds to avoid fainting.
Normal range = should be able to blow 70% of your total lung capacity (FVC) in 1 second. (arguably up to 80%, dependant on your country's Health Dept view)
Fev 1 is measured in litres, so 2 or 3 litres, or thereabout. If big number like 40, 60, 80 etc that will be % of predicted - that which is expected from 'normal lungs' of a person your height, age & gender.
Men have almost always have significantly bigger lungs than women, and so different norms.
Predicted number is an average of normal for your gender, that include big people with small lungs and small people with big lungs.
So taken by itself Fev1 could look 'obstucted' because your blow is less than average... but you could have smaller than average lungs thus actually be normal..
Someone else could blow 90% predicted but have bigger than average lungs and actually be obstructed.
So they need to take into account the size of your own lungs hence the ratio of blow(FEV1) to volume (FVC) where Fev1 divided by FVC (FEV1/FVC) = 75%, arguably, is bottom of the normal range, or top of the obstructed.. depending on age, symptoms and on history - middle aged (ex)smokers with symptoms likely to be deemed mildly obstructed.