Physical symptoms include rapid heart rate and/or heart palpitations, difficulty breathing, dry mouth, shakiness or dizziness, muscle tension, sweating, nausea or gastrointestinal problems, insomnia and restlessness. Mental symptoms include uncontrollable worry (also called “rumination”), feelings of dread or doom, difficulty concentrating, irritability and avoidance of triggers (people, places, things, or situations) that worsen your anxiety symptoms.