G'day Siraj, It is likely that you are experiencing an irritant
exposure of some kind.
Minute particles tend to be collected in the upper breathing and throat
kinds of airway areas and produce an effect.
This may be dust of one kind or another or some other airborne
substance or fume.
It is quite often a forerunner to an allergy condition which needs to
be accurately determined as early as possible for least long-term
effect.
It may well be worthwhile having a scratch-type (or equivalent) allergy
test to try to determine what the problem cause might be.
Careful analysis of your exposure possibilities may allow you to
determine something.
There are other routines which can help.
Try not to be dependent on drugs.
Cheers, Merlin.