Anxiety

Anxiety, unpleasant and disturbing emotion, ranging from ill-defined discomfort to panic or a profound sense of impending doom.

Anxious people may be irritable, restless, and agitated, or have impulses for physical activity that may be purposeless and aimless. Physical symptoms may include an increase in heart rate and blood pressure, generalized or localized muscle tension, rapid and shallow breathing, sighing or shortness of breath, dizziness, or nausea.

Anxiety may be acute, lasting a few minutes to a few hours, or chronic, with symptoms mild to moderate in intensity but almost constantly present. The chronic state may be intermittently and unpredictably accompanied by acute increases in the severity of the symptoms.

Anxiety is usually brought on by stress, which may be well defined and external or ill defined and internal. While it is often thought that anxiety is always undesirable and to be avoided, human personality development studies have demonstrated that tolerable levels of age-appropriate anxiety are largely responsible for individuals' gradual establishment of sophisticated, self-reliant behavior, attitudes, and values.

See also: Phobia.