Ansiedad

"Many people go to the doctor because they feel unwell without knowing exactly what is happening to them in a physical sense. Deep down, what they are experiencing is emotional discomfort, even if they are not fully aware of it," says Bisquerra. This is anxiety, a negative emotion equivalent to a potentially harmful form of stress.
"It is a disproportionate emotional response to a possible but unlikely danger. Anxiety is the anticipation of danger—one that may never come." It triggers a set of physiological responses such as tachycardia, increased respiratory rate, sweating, etc., and involves operant responses of escape or avoidance.
"It results from a persistent feeling of failure or frustration, generating various forms of misfortune-related feelings and, in its acute and chronic forms, even organic illnesses," explains Bisquerra.
The anxiety pentagon includes depression, disorganization (difficulty making decisions), dependency, defense, and defiance (a strong desire for authority).
Some techniques for reducing anxiety include relaxation, breathing exercises, biofeedback, systematic desensitization, implosion therapy, modeling, social skills training, Beck's cognitive therapy, rational emotive therapy, stress inoculation training, and more.