Anxiety is a psychological and physiological state characterized by cognitive, somatic, emotional, and behavioral components.Seligman, M.E.P., Walker, E.F. & Rosenhan, D.L. (2001). Abnormal psychology, (4th ed.) New York: W.W. Norton & Company, Inc. These components combine to create an unpleasant feeling that is typically associated with uneasiness, fear, or worry.

Anxiety is a generalized mood condition that occurs without an identifiable triggering stimulus. As such, it is distinguished from fear, which occurs in the presence of an external threat. Additionally, fear is related to the specific behaviors of escape and avoidance, whereas anxiety is the result of threats that are perceived to be uncontrollable or unavoidable.

Anxiety is a normal reaction to stress. It may help a person to deal with a difficult situation, for example at work or at school, by prompting one to cope with it. When anxiety becomes excessive, it may fall under the classification of an anxiety disorder.

Symptoms

Anxiety can be accompanied by physical effects such as heart palpitations, fatigue, nausea, chest pain, shortness of breath, stomach aches, or headaches. Physically, the body prepares the organism to deal with a threat. 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 (the fight or flight response). External signs of anxiety may include pale skin, sweating, trembling, and pupillary dilation. Someone suffering from anxiety might also experience it as a sense of dread or panic.

Although panic attacks are not experienced by every anxiety sufferer, they are a common symptom. Panic attacks usually come without warning, and although the fear is generally irrational, the perception of danger is very real. A person experiencing a panic attack will often feel as if he or she is about to die or pass out. Panic attacks may be confused with heart attacks.

Anxiety does not only consist of physical symptoms. There are many emotional symptoms involved as well. Some of them include: "Feelings of apprehension or dread, trouble concentrating, feeling tense or jumpy, anticipating the worst, irritability, restlessness, watching (and waiting) for signs (and occurences) or danger, and, feeling like your mind's gone blank." There's also, "nightmares/bad dreams, obsessions about sensations, deja vu, a trapped in your mind feeling, and feeling like everything is scary."

One of the most common symptoms of anxiety is fear, which includes the fear of dying. "You may...fear that the chest pains physical symptom of anxiety are a deadly heart attack or that the shooting pains in your head physical symptom of anxiety are the result of a tumor or aneurysm. You feel an intense fear when you think of dying, or you may think of it more often than normal, or can't get it out of your mind."