An anxiety or panic attack often comes on suddenly, with symptoms peaking within 10 minutes. For doctors to diagnose a panic attack, they look for at least four of the following signs: sweating, trembling, shortness of breath, a choking sensation, chest pain, nausea, dizziness, fear of losing your mind, fear of dying, feeling hot or cold, numbness or tingling, a racing heart (heart palpitations), and feeling unusually detached from yourself.
People with panic disorder have sudden and repeated attacks of fear that last for several minutes or longer. These are called panic attacks. Panic attacks are characterized by a fear of disaster or of losing control even when there is no real danger. A person may also have a strong physical reaction during a panic attack. It may feel like having a heart attack. Panic attacks can occur at any time, and many people with panic disorder worry about and dread the possibility of having another attack.
It is not clear what causes panic disorder. In many people who have the biological vulnerability to panic attacks, they may develop in association with major life changes (such as getting married, having a child, starting a first job, etc.) and major lifestyle stressors. There is also some evidence that suggests that the tendency to develop panic disorder may run in families. People who suffer from panic disorder are also more likely than others to suffer from depression, attempt suicide, or to abuse alcohol or drugs.
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. 
Melissa Conrad Stöppler, MD, is a U.S. board-certified Anatomic Pathologist with subspecialty training in the fields of Experimental and Molecular Pathology. Dr. Stöppler's educational background includes a BA with Highest Distinction from the University of Virginia and an MD from the University of North Carolina. She completed residency training in Anatomic Pathology at Georgetown University followed by subspecialty fellowship training in molecular diagnostics and experimental pathology.
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.