Compulsions: These are repetitive behaviors or mental acts that individuals with obsessions feel compelled to perform in order to alleviate anxiety caused by the obsessions.
Intrusive Thoughts: Similar to obsessions, these are unwanted thoughts that pop into one's mind without intentional control.
Anxiety Disorders: Obsessive-compulsive disorder (OCD) is classified as an anxiety disorder because it involves excessive worry and fear associated with the obsessions and compulsions.