Obsessive-compulsive disorder (OCD) is an anxiety disorder characterized by unwanted and repeated thoughts (obsessions) and behaviors (compulsions) performed to temporarily relieve anxiety. Common obsessions include fears of contamination or acting improperly, while compulsions include excessive washing or repeating phrases. OCD is often treated using medication like SSRIs and cognitive behavioral therapy, which exposes patients to anxiety-inducing situations to resist compulsions. Long-term, OCD is a chronic condition with periods of severe symptoms and improvement, though complete remission is rare.