Anxiety is a complex combination of negative emotions that includes fear, apprehension and worry, and is often accompanied by physical sensations such as palpitations, nausea, chest pain and/or shortness of breath.
Anxiety is often described as having cognitive, somatic, emotional, and behavioral components (Seligman, Walker & Rosenhan, 2001). The cognitive component entails expectation of a diffuse and uncertain danger. Somatically the body prepares the organism to deal with threat (known as an emergency reaction); blood pressure and heart rate are increased, sweating is increased, bloodflow to the major muscle groups is increased, and immune and digestive system functions are inhibited. Externally, somatic signs of anxiety may include pale skin, sweating, trembling, and pupillary dilation. Emotionally, anxiety causes a sense of dread or panic and physically causes nausea, and chills. Behaviorally, both voluntary and involuntary behaviors may arise directed at escaping or avoiding the source of anxiety. These behaviors are frequent and often maladaptive, being most extreme in anxiety disorders. However, anxiety is not always pathological or maladaptive: it is a common emotion along with fear, anger, sadness, and happiness, and it has a very important function in relation to survival .
Neural circuitry involving the amygdala and hippocampus is thought to underlie anxiety (Rosen & Schulkin, 1998). When confronted with unpleasant and potentially harmful stimuli such as foul odors or tastes, PET-scans show increased bloodflow in the amygdala (Zald & Pardo, 1997; Zald, Hagen & Pardo, 2002). In these studies, the participants also reported moderate anxiety. This might indicate that anxiety is a protective mechanism designed to prevent the organism from engaging in potentially harmful behaviors such as feeding on rotten food.
A chronically recurring case of anxiety that has a serious effect on a person's life may be clinically diagnosed as an anxiety disorder. The most common are generalized anxiety disorder, panic disorder, social anxiety disorder, phobias, obsessive-compulsive disorder, and posttraumatic stress disorder (PTSD).
Test anxiety is the uneasiness, apprehension, or nervousness felt by students who have a fear of failing an exam. Students suffering from test anxiety may experience any of the following: the association of grades with personal worth, embarrassment by a teacher, taking a class that is beyond their ability, fear of alienation from parents or friends, time pressures, or feeling a loss of control. Emotional, cognitive, behavioral, and physical components can all be present in test anxiety. Sweating, dizziness, headaches, racing heartbeats, nausea, fidgeting, and drumming on a desk are all common. An optimal level of arousal is necessary to best complete a task such as an exam; however, when the anxiety or level of arousal exceeds that optimum, it results in a decline in performance. Because test anxiety hinges on fear of negative evaluation, debate exists as to whether test anxiety is itself a unique anxiety disorder or whether it is a specific type of social phobia.