A feeling of worry, nervousness, or unease, typically about an imminent event or something with an uncertain outcome. In some cases, anxiety is a mental health condition that requires treatment. Generalized anxiety disorder, for example, is characterized by persistent worry about major or minor concerns. Other anxiety disorders — such as panic disorder, obsessive-compulsive disorder (OCD) and post-traumatic stress disorder (PTSD) — have more-specific triggers and symptoms.