Social Anxiety Disorder;Fear of social situations in which the person is exposed to unfamiliar people or to possible scrutiny by others. The individual fears that he or she will act in a way (or show anxiety symptoms) that will be embarrassing and humiliating, often times leading to avoidance of social situations and severe distress when participation in social situations can't be avoided. 
These attacks are a symptom of panic disorder, a type of anxiety disorder that affects some 2.4 million U.S. adults. The disorder most often begins during the late teens and early adulthood and strikes twice as many American women as men. No one knows what causes panic disorder, though researchers suspect a combination of biological and environmental factors, including family history (panic disorder seems to run in families), stressful life events, drug and alcohol abuse, and thinking patterns that exaggerate normal physical reactions.
Hyperventilation syndrome may occur when a person breathes from the chest, which can lead to overbreathing (exhaling excessive carbon dioxide in relation to the amount of oxygen in one's bloodstream). Hyperventilation syndrome can cause respiratory alkalosis and hypocapnia. This syndrome often involves prominent mouth breathing as well. This causes a cluster of symptoms, including rapid heart beat, dizziness, and lightheadedness, which can trigger panic attacks.
While obsessive-compulsive disorder is not officially classified by the American Psychological Association as an anxiety disorder, it shares many traits with common anxiety disorders, such as generalized anxiety disorder. In both conditions, you may know that your thoughts are irrational, but you feel unable to stop thinking them. Often, but not always, these thoughts may concern cleanliness, sex, or religion.
It is important to note that many people may experience a panic attack once, or even a few times during their lives and may never develop an anxiety disorder. “Anxiety attacks” that are correlated to specific real dangers are not usually a problem. In fact, this type of anxiety is normal. Since the symptoms of anxiety and panic attacks may mimic many other medical and psychological disorders, it is important to review your symptoms with your doctor for an accurate diagnosis.
Occasional anxiety is an expected part of life. You might feel anxious when faced with a problem at work, before taking a test, or before making an important decision. But anxiety disorders involve more than temporary worry or fear. For a person with an anxiety disorder, the anxiety does not go away and can get worse over time. The symptoms can interfere with daily activities such as job performance, school work, and relationships.