Fear and anxiety are a normal--even essential--part of life. They prepare us for danger, creating physiological changes that enable us to effectively respond to a threat. Fear is very straightforward. It arises in response to immediate danger, so it is usually unexpected, very intense, and limited to the situation at hand. Your response to the fear, such as jumping out of the path of an oncoming car, quickly resolves the situation.

Anxiety, on the other hand, is more general and complex. It is felt in anticipation of danger, and is associated with the ability to predict, prepare for, and adapt to change. Often, it lasts a long time, and its cause remains ill-defined. For example, someone uneasy about public speaking may experience a tightness in the stomach for days before a scheduled talk.

Thousands of scientific studies over the past several years show that high blood pressure, ulcers, migraine headaches, strokes, alcoholism, depression, anger, fatigue, drug addiction and many other medical conditions are often due to the long-term effects of stress.

Although anxiety disorders take several distinct forms, certain general symptoms tend to appear in all of them. When discussing their condition, people with anxiety disorders often report the following: - cold/clammy hands - diarrhea - dizziness - dry mouth - fast pulse - fatigue - jitteriness - lump in the throat - muscle aches - numbness/tingling of hands, feet, or other body part - racing or pounding heart - rapid breathing - shakiness - sweating - tension - trembling - upset stomach

The hallmark of this problem is chronic worry and tension with no apparent cause. People suffering from generalized anxiety disorders may worry excessively about health, money, family, or work, often anticipating disaster. Although they are usually aware that their anxiety is more intense than necessary, they can't seem to let it go. Constant worrying contributes to trouble sleeping and relaxing. People with anxiety disorders may startle easily and have trouble concentrating. Generalized anxiety disorder often leads to depression.

Symptoms of this disorder are often mild, and do not interfere with work or social situations. If symptoms are severe, however, they can disrupt daily activities. Because people with generalized anxiety disorder often have another physical or emotional disorder, such as depression, there has been much learned debate as to whether anxiety disorder exists on its own. But recent studies indicate that there really is such a disorder, and that it can be helped by diagnosis and treatment. The symptoms of generalized anxiety disorder usually begin in youth and may go untreated for decades. However, they tend to diminish with age. One study found that only 3 percent of cases of generalized anxiety disorder began in those 65 and over. The problem is more common among women than men and often runs in families.

Biochemical theory suggests that biologic imbalances, perhaps among the neurotransmitters in the brain, may be the primary cause of anxiety disorders. Indeed, in one study researchers were able to trigger a panic attack in some people simply by infusing certain chemicals. Many scientists involved in anxiety research now argue that correcting biochemical imbalances with medication should be the first goal of treatment. Other studies suggest that biochemical changes can also be achieved through the psychological and behavioral changes produced by psychotherapy.

Learning theory views anxiety as a learned behavior that can be unlearned. This theory posits that a person's anxiety can be reduced by persistently confronting the feared situation or object. And some people do, in fact, change their thinking and experience significant relief without any medication.

Stress, trauma, uncertainty. Most theorists agree that, other factors aside, stress, trauma, and uncertainties can play a role in the development of anxiety disorders. Studies show a relationship between anxiety and stress, which can be defined as a consequence of adapting to a change. Challenges such as the death of a loved one require a major adaptation that can contribute to the development of an anxiety disorder. Uncertainty during transitions, or about the future, can also produce anxiety. Some studies have found that a stressful event precedes the appearance of many anxiety disorders, though this result is not yet conclusive. The influence of these factors appears to vary with the disorder. In post-traumatic stress syndrome, such factors play a major role, whereas in obsessive- compulsive disorder, brain chemistry appears to be the primary culprit.

Although it's uncommon, certain medical problems can mimic the symptoms of anxiety, or even produce it. The palpitations and shortness of breath caused by an irregular heartbeat can easily be mistaken for anxiety. A clot in the lung (pulmonary embolism) often causes unexplained feelings of anxiety. Neurological problems such as epilepsy and brain disorders can be responsible for symptoms of anxiety. So can anemia, diabetes, thyroid disease, and adrenal problems. In general, these symptoms will disappear when the underlying disease is brought under control, although the anxiety sometimes requires separate treatment.

Prescription drugs and those purchased over the counter also can cause anxiety symptoms. Cold medicines, diet pills, antispasmodic medications, stimulants, digitalis, thyroid supplements, and, paradoxically, antidepressants given to reduce panic all may cause anxiety. Discontinuing a variety of drugs, including tranquilizers, sleeping pills, and certain blood-pressure medicines can lead to withdrawal symptoms that often include anxiety.

Also, research indicates that other brain parts called the basal ganglia and striatum are involved in obsessive-compulsive disorder.

By learning more about brain circuitry involved in fear and anxiety, scientists may be able to devise new and more specific treatments for anxiety disorders. For example, it someday may be possible to increase the influence of the thinking parts of the brain on the amygdala, thus placing the fear and anxiety response under conscious control.

In addition, with new findings about neurogenesis (birth of new brain cells) throughout life, perhaps a method will be found to stimulate growth of new neurons in the hippocampus in people with post-traumatic stress disorder.

Terms explaining

Anxiety

• A state of uneasiness and apprehension, as about future uncertainties.


• Worry or tension in response to real or imagined stress, danger, or dreaded situations. Physical reactions such as fast pulse, sweating, trembling, fatigue, and weakness may accompany anxiety.

Anxiety disorder

• A psychiatric disorder involving the presence of anxiety that is so intense or so frequently present that it causes difficulty or distress for the individual.

Anxiety disorders

• Any of various disorders in which anxiety is either the primary disturbance or is the result of confronting a feared situation or object; they include obsessive-compulsive disorder and posttraumatic stress disorder.

Fear

• Fear is an unpleasant feeling of perceived risk or danger, whether it be real or imagined.

Depression

• In psychiatry, a symptom of mood disorder characterized by intense feelings of loss, sadness, hopelessness, failure, and rejection.

Mental health

• A state of emotional and psychological well-being in which an individual is able to use his or her cognitive and emotional capabilities, function in society, and meet the ordinary demands of everyday life.


• The psychological state of someone who is functioning at a satisfactory level of emotional and behavioral adjustment.

Stress

• A state of extreme difficulty, pressure, or strain.


• A physical and psychological response that results from being exposed to a demand or pressure.

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