Anxiety is a common, often debilitating, mental health diagnosis that causes intense, uncontrollable, and irrational worrying and/or fear. Anxiety affects how someone thinks, feels, and acts; and interferes with their ability to function and enjoy life. It's common for people suffering from anxiety to feel unable to cope with everyday situations as well as to experience feelings of restlessness and irritability. Anxiety can cause physical symptoms like upset stomach, chest pain, difficulty breathing, pounding heartbeats, feelings of dread, and headaches or migraines.