Anxiety symptoms refer to physical and psychological signs that indicate a person is experiencing anxiety. These can include feelings of worry, nervousness or fear; restlessness or difficulty sitting still; tension or feeling on edge; rapid heartbeat or palpitations; sweating; trembling or shaking; difficulty breathing or shortness of breath; chest pain or discomfort; nausea or upset stomach; dizziness or lightheadedness; headaches; fatigue or lack of energy; irritability or feelings of being on edge; difficulty concentrating, or other physical symptoms. The severity and duration of anxiety symptoms can vary from person to person, and may be a sign of an underlying mental health condition such as generalized anxiety disorder (GAD) or panic disorder.