Insight into excessive anxiety:
People who suffer from OCD are aware that their thoughts are not rational.
This is necessary for a diagnosis of OCD.
If obsessive thoughts were based on reality then would be a symptom of a different disorder,
OCD sufferers experience catastrophic thoughts about the worst case scenarios that might result if anxieties were justified.
Tend to be hypervigilant, e.g. they maintain constant alertness and keep attention to focus on potential hazards.