People who are paranoid may manifest several other related symptoms. Continual mistrust and suspicion are closely associated with paranoia. People who are paranoid tend to view the world as threatening and regularly confirm their suspicions with even the smallest piece of evidence that supports these views. For instance, they may view cancellation of a dinner date as a sign that all people are untrustworthy.

Hypersensitivity is another symptom closely related to paranoia. This may lead a person to be offended by a simple comment or gesture that was not intended to be injurious. Hypersensitivity can cause a person to be defensive and antagonistic, and leave them unable to bear even slight criticism. Despite their own hypersensitivity to criticism, paranoid people tend to be highly critical of others.