Lung infection perhaps?
Possibly a flare up of COPD if there's any history, especially if a smoker or recently quit.
if sudden and persistent then could be a small pneumothorax (I've had 7 or 8 of those over the years) especially if, on top of the wheezing, it feels like you've inhaled something solid that you can't cough up.
if I think of any more good news I'll let you know
