Anxiety Health Article

Definition

Anxiety is a bodily response to a perceived threat or danger. It is triggered by a combination of biochemical changes in the body, the patient's personal history and memory, and the social situation.

It is important to distinguish between anxiety as a feeling or experience and an anxiety disorder as a psychiatric diagnosis. A person may feel anxious without having an anxiety disorder. Also, a person facing a clear and present danger or a realistic fear is not usually considered to be in a state of anxiety. In addition, anxiety frequently occurs as a symptom in other categories of psychiatric disturbance.

Description

Anxiety is related to fear, but it is not the same thing. Fear is a direct, focused response to a specific event or object of which an individual is consciously aware. Most people will feel fear if someone points a loaded gun at them or if they see a tornado forming on the horizon. They also will recognize that they are afraid. Anxiety, on the other hand, is often unfocused, vague, and hard to pin down to a specific cause.

Sometimes anxiety experienced in the present may stem from an event or person that produced pain and fear in the past. In this experience, the anxious individual may not be consciously aware of the original source of the feeling. Anxiety has an aspect of remoteness that makes it hard for people to compare their experiences. Whereas most people will be fearful in physically dangerous situations, and can agree that fear is an appropriate response in the presence of danger, anxiety is often triggered by objects or events that are unique and specific to an individual. An individual might be anxious because of a unique meaning or memory being stimulated by present circumstances, not because of some immediate danger.

Causes & symptoms

Anxiety is characterized by the following symptoms:

• Somatic. These physical symptoms include headaches, dizziness or lightheadedness, nausea and/or vomiting, diarrhea, tingling, pale complexion, sweating, numbness, difficulty in breathing, and sensations of tightness in the chest, neck, shoulders, or hands. These symptoms are produced by the hormonal, muscular, and cardiovascular reactions involved in the fight-or-flight reaction.
• Behavioral. Behavioral symptoms of anxiety include pacing, trembling, general restlessness, hyperventilation, pressured speech, hand wringing, and finger tapping.
• Cognitive. Cognitive symptoms of anxiety include recurrent or obsessive thoughts, feelings of doom, morbid or fear-inducing thoughts or ideas, and confusion or inability to concentrate.
• Emotional. Emotional symptoms include feelings of tension or nervousness, feeling "hyper" or "keyed up," and feelings of unreality, panic, or terror.

Anxiety can have a number of different causes. It is a multidimensional response to stimuli in the person's environment, or a response to an internal stimulus (for example, a hypochondriac's reaction to a stomach rumbling) resulting from a combination of general biological and individual psychological processes.

Physical triggers

In some cases, anxiety is produced by physical responses to stress or by certain disease processes or medications.

THE AUTONOMIC NERVOUS SYSTEM (ANS). The nervous system of human beings is hard-wired to respond to dangers or threats. These responses are not subject to conscious control and are the same in humans as in lower animals. They represent an evolutionary adaptation to animal predators and other dangers that all animals—including primitive humans—had to cope with.

The most familiar reaction of this type is the fight-or-flight reaction to a life-threatening situation. When people have fight-or-flight reactions, the level of stress hormones in their blood rises. They become more alert and attentive, their eyes dilate, their heartbeats increase, their breathing rates increase, and their digestion slows down, making more energy available to the muscles.

This emergency reaction is regulated by a part of the nervous system called the autonomic nervous system, or ANS. The ANS is controlled by the hypothalamus, a specialized part of the brainstem that is among a group of structures called the limbic system. The limbic system controls human emotions through its connections to glands and muscles; it also connects to the ANS and higher brain centers, such as parts of the cerebral cortex.

One problem with this arrangement is that the limbic system cannot tell the difference between a real physical threat and an anxiety-producing thought or idea. The hypothalamus may trigger the release of stress hormones from the pituitary gland even when there is no external danger.

A second problem is caused by the biochemical side effects of too many false alarms in the ANS. When a person responds to a real danger, his or her body relieves itself of the stress hormones by facing up to the danger or fleeing from it. In modern life, however, people often have fight-or-flight reactions in situations where they can neither run away nor lash out physically. As a result, their bodies have to absorb all the biochemical changes of hyperarousal rather than release them. These biochemical changes can produce anxious feelings as well as muscle tension and other physical symptoms of anxiety.

DISEASES AND DISORDERS. Anxiety can be a symptom of certain medical conditions. For example, anxiety is a symptom of certain endocrine disorders that are characterized by over activity or under activity of the thyroid gland. Cushing's syndrome, in which the adrenal cortex overproduces cortisol, is one such disorder. Other medical conditions that can produce anxiety include respiratory distress syndrome, mitral valve prolapse, porphyria, and chest pain caused by inadequate blood supply to the heart (angina pectoris).

MEDICATIONS AND SUBSTANCE USE. Numerous medications may cause anxiety-like symptoms as a side effect. They include birth control pills, some thyroid or asthma drugs, some psychotropic agents, corticosteroids, antihypertensive drugs, nonsteroidal anti-inflammatory drugs (such as flurbiprofen and ibuprofen), and local anesthetics. Caffeine can also cause anxiety-like symptoms when consumed in sufficient quantity.

Withdrawal from certain prescription drugs—primarily beta-blockers and corticosteroids—can cause anxiety. Withdrawal from drugs of abuse, including LSD, cocaine, alcohol, and opiates, can also cause anxiety.