Anxiety is a normal, but highly subjective, human emotion. While normal anxiety serves a beneficial and adaptive purpose, anxiety can also become the cause of tremendous suffering for millions of people. Working from a biopsychosocial perspective, this article provided an overview of the origin and functional purpose of normal anxiety. The biological, psychological, and social factors that contribute to the formation and maintenance of (pathological) anxiety disorders were presented. The various anxiety disorders, theories, and associated treatments were reviewed. The treatment for anxiety disorders is based on a solid scientific foundation, grounded in research by experts from diverse fields. The research has investigated these biological, social, and psychological factors that contribute to anxiety disorders. This broad research base has led to the development of numerous, empirically-based treatments that have proven to be highly effective. As a result, thousands of courageous individuals have reclaimed their health, restored their functioning, and now enjoy richly rewarding and satisfying lives. The future remains optimistic for those who struggle with anxiety. We are confident that advancements in the treatment of anxiety disorders will continue to bring hope and relief to the people, and families, affected by these disorders.