As long as anxiety disorders are viewed as individual burdens restricted to individual clients, it is difficult to convince society to treat anxiety disorders with the same concern accorded other psychiatric-mental health disorders. Anxiety disorders are costly. These costs are not restricted to individual clients. They also involve employers, health insurance providers, and the national economy. The true costs of treating anxiety disorders cannot be fully determined without an assessment of the adequacy of available treatments. This chapter focuses on theories, clinical symptoms, and nursing process related to the spectrum of anxiety disorders.