When we experience an involuntary high degree stress response, the sensations can be so profound that we think we are having a medical emergency, which anxious personalities can react to with more fear. And when we become more afraid, the body is going to produce another stress response, which causes more changes, which we can react to with more fear, and so on.
An evolutionary psychology explanation is that increased anxiety serves the purpose of increased vigilance regarding potential threats in the environment as well as increased tendency to take proactive actions regarding such possible threats. This may cause false positive reactions but an individual suffering from anxiety may also avoid real threats. This may explain why anxious people are less likely to die due to accidents.
Generalized anxiety disorder is a condition in which your worries overwhelm you to the point where your daily routine seems difficult to carry out, and you have been worrying this way for at least six months. You may feel on edge and have difficulty focusing on tasks. There may be a tendency to fear and expect the worst; some call this catastrophic thinking. You even may know that your worries are perhaps irrational, but you still go on feeling them.
In an anxiety-related disorder, your fear or worry does not go away and can get worse over time. It can influence your life to the extent that it can interfere with daily activities like school, work and/or relationships. Fear, stress, and anxiety are "normal feelings and experiences" but they are completely different than suffering from any of the seven diagnosable disorders plus substance-induced anxiety, obsessive-compulsive disorders, and trauma- or stressor-related disorders.
While the term "test anxiety" refers specifically to students, many workers share the same experience with regard to their career or profession. The fear of failing at a task and being negatively evaluated for failure can have a similarly negative effect on the adult. Management of test anxiety focuses on achieving relaxation and developing mechanisms to manage anxiety.
The degree of accompanying stress response and its physiological, psychological, and emotional changes are directly proportional to the degree of anxiety. For example, if you are only slightly concerned, such as being slightly nervous about meeting someone new, the body produces a small degree stress response. The small degree stress response can be so slight that you don’t even notice it.