Paranoia is thinking and feeling like you are being threatened in some way, even if there is no evidence, or very little evidence, that you are. Paranoid thoughts can also be described as delusions. There are lots of different kinds of threat you might be scared and worried about.
Paranoid thoughts could also be exaggerated suspicions.
Link to article: https://www.mind.org.uk/information-support/types-of-mental-health-problems/paranoia/about-paranoia/