As we all know there is a gray area between halal and haram which one should avoid.
What is lawful is evident and what is unlawful is evident, and in between them are the things doubtful which many people do not know. So he who guards against doubtful things keeps his religion and honour blameless, and he who indulges in doubtful things indulges in fact in unlawful things, just as a shepherd who pastures his animals round a preserve will soon pasture them in it. Beware, every king has a preserve, and the things God his declared unlawful are His preserves. Beware, in the body there is a piece of flesh; if it is sound, the whole body is sound and if it is corrupt the whole body is corrupt, and hearken it is the heart. (Muslim, 1599)
But on the other hand Islam also teaches not to doubt unnecessarily for instance when during prayer when you doubt if your wudu is broken or doubting if water is clean without any color or smell. If someone keeps doubting, the doubt keeps on increasing and might become a disease (OCD).
So how can someone differentiate between that gray area and the doubt? For example, having doubt if the meat that wasn't slaughtered in front of your eyes have chances of being Haram. This is just an example but how can someone differentiate these doubts from what hadith actually means by "الشُّبُهَاتِ"?