Anxiety is a normal feeling of uneasiness, concern and apprehension that, when carried to an extreme, can become worry or outright terror. Some amount of anxiety and worrying is a normal and necessary part of life. It is because we are concerned about our children's safety, for example, that we watch them carefully when we are at the beach. It is because we are concerned about our own well-being that we fasten our seatbelts when we get into a car. These kinds of concerns help keep us aware and alert, but don't interfere with our daily life in any way. On the contrary, worry on this level means that our internal protective systems are doing what they are supposed to do.

Anxiety rooted in stress is what is commonly known as "fight-or-flight." It is a physical and emotional response to real or perceived danger. This kind of anxiety, although it can be very uncomfortable, is still very useful in that it helps us respond to a crisis. Intense worry about a sick child prompts us to prepare for any eventuality, for better or for worse.

Stress anxiety is caused by a clearly identifiable event and fades as soon as the crisis is over. (Amusement parks make a great deal of their money by provoking this kind of anxiety. The jolt in your stomach when you speed down a roller coaster or when something jumps out at you is the fight-or-flight response in action. The rush of adrenaline feels so good, you want to take another ride.)

When Does Normal Anxiety Become an Anxiety Disorder?

Anxiety disorders take normal anxiety responses to another level. For people with anxiety disorders, worrying (and/or worrying about worrying) disrupts the flow of daily life. These worries and even the fight-or-flight adrenaline rush are not necessarily connected to any specific event. Often they happen for no apparent reason, and disappear as mysteriously as they started. What best characterizes an anxiety disorder is that it is out of proportion and out of the control of the individual.

Anxiety Disorders are divided into six major categories: generalized anxiety disorder (GAD), panic disorder, phobias, obsessive-compulsive disorder, acute stress disorder, and post-traumatic stress disorder. Because the symptoms of each category overlap somewhat, it is not uncommon for someone to be diagnosed with more than one anxiety disorder at any given time. These disorders are collectively relatively common; at least three percent of the U.S. population has experienced an anxiety disorder.

What Causes an Anxiety Disorder?

No one knows for sure. There is evidence that some people are born more prone to anxiety than others, and evidence that societal factors play a large role as well. Parents with a tendency to be overly anxious can pass that tendency on to their children. Unsupportive or abusive families can cause the development of anxiety disorders as well. Still others develop anxiety disorders because they are exposed to a traumatic event like an accident, natural disaster, or severe abuse that makes them question their basic safety in the world. As a general rule, studies indicate that women are twice as likely to develop anxiety disorders as men.

Finally, there are some physical conditions that make people act like they are having panic attacks or anxiety. Among these are hypoglycemia, hypothyroidism, hyperthyroidism, a mitral valve prolapse, inner ear problems, congestive heart failure, deficiencies of certain minerals and vitamins, withdrawal (like nicotine withdrawal), and PMS.

TYPES OF ANXIETY DISORDERS: Descriptions and case studies

Anxiety disorders come in many varieties. Descriptions of some of the most common disorders follow:

Generalized Anxiety Disorder: GAD is characterized by persistent anxiety, unrelated to a specific event. People suffering from GAD cannot help worrying about anything and everything, even in calm situations. They have difficulty relaxing, falling asleep, and/or concentrating, and tend to be impatient and irritable. Physical symptoms accompanying GAD include sweating; an upset stomach; diarrhea; frequent urination; cold, clammy hands; a lump in the throat; a dry mouth; shortness of breath; headaches; and dizziness. Managing the normal demands of a job, relationships, and everyday life can become more and more difficult for people with this disorder. GAD appears in four percent of the general population.

Case Study: Amy, age 38, is a worrier. She is restless, irritable and has difficulty concentrating. She worries that she worries so much and isn't always sure what it is that she is worried about. She can't let her husband or children leave the house without making them call her regularly to reassure her that they are okay. Her husband is growing weary of her fretting. Her children can't understand what all the fuss is about. Their impatience with her only makes her worry more. Amy has generalized anxiety disorder.

Panic Disorder: Panic attacks are just that – sudden, unexplainable waves of panic that seem to come out of the blue. The body responds with the "fight-or-flight" response, anticipating clear and immediate danger. Often, these attacks subside as mysteriously as they occur. A person who has experienced one or more panic attacks often develops a fear of having one again. Some professionals call this a "fear of fear." The individual may even try to stay away from anything that reminds him or her of the last attack to avoid having another one. People can have panic attacks with or without agoraphobia (see "Phobias" below).

These attacks include symptoms such as heart palpitations, shortness of breath, chest pain, feelings of choking or smothering, nausea, dizziness, sweating, and trembling. An afflicted person might also be overwhelmed by a fear of dying, going crazy, or losing control.

Case Study: Annie is a 20-year-old student at a local community college. On several occasions recently, she has experienced sudden, absolute panic. During these episodes, her heart pounds; she trembles; her mouth gets dry and it feels as if the walls are caving in. The feelings only last a few minutes but, when they occur, the only thing that seems to relieve her fear is walking around her apartment and reminding herself that she is in control. She won't ride in cars any more unless she is driving so she is sure that she can stop if necessary. She will only go to class if she can find an aisle seat in the back row so that she can leave quietly should she have another attack. She avoids any situation in which she might feel out of control or embarrassed by her own terror. Annie is suffering from panic attacks.

Phobias: Phobias are attempts to compartmentalize fear into a few situations that can be avoided. By attaching all the panicky feelings onto a few situations, the person can avoid those situations and go on with life. Unfortunately, phobias can take on a life of their own and take over more and more of a person's life. A fear of dogs can, for example, be fairly easy to manage – just don't go near dogs. But a fear of flying may limit social and business opportunities.

Some of the more common phobias include claustrophobia (fear of closed spaces), agoraphobia (fear of public places, sometimes related to panic attacks), and acrophobia (fear of heights).

Case Study: Hannah, age 55, was in a major car accident 20 years ago during a cross-country trip. Ever since, she has been unable to drive on major highways. Although she does drive, she goes to great lengths to travel only on back roads and scenic routes. She is able to go where she wants to go but it often takes much longer to get there than it should. Hannah has developed a phobia about highway driving.

Obsessive-Compulsive Disorder: Although classified as an anxiety disorder, obsessive-compulsive disorder (OCD) differs from these disorders in significant ways. It is the one anxiety diagnosis that seems to have a clear biological cause. Unlike the other kinds of anxiety disorders, talk therapy alone isn't much help. Medication is also necessary.

OCD is a disorder in which the mind is flooded with involuntary thoughts, or in which an individual feels compelled to repeat certain acts over and over again (for example, hand washing). This disorder can interfere significantly with everyday living, and usually leads to concern and/or resentment among friends, family, and co-workers.

A person who suffers from OCD doesn't want the thoughts and doesn't want to do the behaviors. Unfortunately, he or she really can't help it. About half the people with OCD report that it began in childhood; most others start in adolescence or early adulthood. OCD affects approximately two percent of the general population.

Case Study: Bert is 40 years old and works on an assembly line in a brush factory. He is terribly afraid of being contaminated by germs. He avoids shaking hands with others. He won't eat in the cafeteria. He has trouble leaving the bathroom because he isn't sure he has washed his hands well enough. Bert is suffering from obsessive compulsive disorder.

Acute Stress Disorder: Acute stress disorder can occur within a month of experiencing or witnessing a traumatic event. It lasts from two days to no more than four weeks. Either during the event or in the month following it, the individual develops at least three of the following symptoms: numbing of feelings or emotional detachment; being "in a daze"; memory gaps or a kind of selective amnesia for the event or details of the event; and/or a sense of feeling unreal. The person re-experiences the trauma through dreams, nightmares, flashbacks, or a sense of reliving the experience. He or she may become extremely upset by anything that reminds him or her of the event and may go to great lengths to avoid anything that might trigger a reminder. Symptoms of anxiety may occur or increase, including sleep disturbance, difficulty concentrating, restlessness, and hyperalertness. All this makes it very difficult for the person to manage relationships, job or school, or the tasks of everyday life.

Case Study: Two weeks ago, Leo, age 25, was hunting with his best friend when his friend tripped over a root and accidentally shot himself to death. He doesn't remember exactly how he got himself and his friend's body out of the woods. Every night he has nightmares about not being able to save him, making it almost impossible to sleep. He can't concentrate or stay focused during conversations. Most of the time, he says he feels numb. But when asked to talk about what happened, he gets very upset. Leo is suffering from acute stress disorder.

Posttraumatic Stress Disorder: Posttraumatic stress disorder (PTSD) can develop in the wake of a traumatic event that is outside the usual human experience. A person either experiences direct or threatened injury, or witnesses the serious injury or death of another. In some cases, learning of the unexpected death or injury of a loved one can also bring on symptoms of PTSD. For a diagnosis of PTSD to be made, there must be both an identifiable terrifying event and a response of intense fear, helplessness and horror, as well as one or more characteristic symptoms. These include:

-Re-experiencing of the event through nightmares, daytime flashbacks, and/or physical sensations that recall the feelings present during the event. In children, this can take the form of repetitive play that contains aspects of the traumatic event.

-Numbing and shutting down feelings and memory. Feeling detached from others. Dissociating from the distressing memories and feelings.

-Hyperalertness to danger. The individual often has difficulty shutting down the fight-or-flight response that was quite appropriately activated during the event. This causes sleeplessness, irritability, difficulty with concentration, and general restlessness, and sometimes the development of an exaggerated startle.

-Hypervigilance and avoidance of any situation associated with the event.

These symptoms significantly disrupt an afflicted person’s daily life. Depending on the type of traumatic event, the person might react with distrust of others, avoidance of anyone or anything that reminds them of the event, or lack of confidence in their ability to keep themselves safe.

Case Study: Joanne, age 32, is involved with the first man that really counts in her life. As the couple has become more intimate, Joanne has started to have flashbacks about an uncle who touched her sexually when she was only eight. She is distressed to find that she is shutting down feelings about her boyfriend and distancing herself from him. Although she has been sexual with other men, she says she can't stand to let herself be sexual with someone she loves and trusts. She startles easily and reports a general increase in anxiety. She is very angry that she has to deal with the feelings about the incidents with her uncle that happened so long ago. She says that she thought she had gotten beyond all that. Joanne is struggling with PTSD.

Treatment of anxiety disorders

Fortunately, there are treatments for anxiety disorders. A combination of medication, cognitive-behavioral therapy, and learning coping and self-soothing strategies often can bring the level of anxiety a person is experiencing down to a manageable level.

More information on anxiety disorders is available from the National Institute of Mental Health at: http://www.nimh.nih.gov/anxiety/anxiety.cfm#anx1