Women are more than two times as likely as men to be diagnosed with an anxiety disorder. (6) It’s not clear why this is the case, but researchers have theorized that it may be due to a combination of social and biological factors. Scientists are still investigating the complex role that sex plays in brain chemistry, but some research suggests that in women, the amygdala, which is the part of the brain responsible for processing potential threats, may be more sensitive to negative stimuli and may hold on to the memory of it longer. (7) 
Psychologically, people who develop panic attacks or another anxiety disorder are more likely to have a history of what is called anxiety sensitivity. Anxiety sensitivity is the tendency for a person to fear that anxiety-related bodily sensations (like brief chest pain or stomach upset) have dire personal consequences (for example, believing that it automatically means their heart will stop or they will throw up, respectively). From a social standpoint, a risk factor for developing panic disorder as an adolescent or adult is a history of being physically or sexually abused as a child. This is even more the case for panic disorder when compared to other anxiety disorders. Often, the first attacks are triggered by physical illnesses, another major life stress, or perhaps medications that increase activity in the part of the brain involved in fear reactions.
People facing anxiety may withdraw from situations which have provoked anxiety in the past.[5] There are various types of anxiety. Existential anxiety can occur when a person faces angst, an existential crisis, or nihilistic feelings. People can also face mathematical anxiety, somatic anxiety, stage fright, or test anxiety. Social anxiety and stranger anxiety are caused when people are apprehensive around strangers or other people in general. Stress hormones released in an anxious state have an impact on bowel function and can manifest physical symptoms that may contribute to or exacerbate IBS. Anxiety is often experienced by those who have an OCD and is an acute presence in panic disorder. The first step in the management of a person with anxiety symptoms involves evaluating the possible presence of an underlying medical cause, whose recognition is essential in order to decide the correct treatment.[6][7] Anxiety symptoms may mask an organic disease, or appear associated with or as a result of a medical disorder.[6][7][8][9]

Anxiety disorders are associated with chronic life stress. Unpredictable, unrelenting, unresolvable stressors chronically stimulate the stress hormone system and cardiovascular system, and lead to states of constant increased activity. Biologically, the body has evolved to deal with imminent and concrete danger in the environment, rather than continuous stressors. Under normal conditions where chronic stress is low, exposure to a sudden threat activates the autonomic nervous system, i.e. increased levels of adrenaline and faster breathing, and racing heart rate. These reactions in turn trigger activation of stress hormones, such as cortisol. One of the effects of these stress hormones is to increase glucose levels in the bloodstream in order to respond to the imminent threat, so that muscles can be activated for the flight or fight response. Another effect of stress hormones is to supress the immune system, since processes such as healing and repair can wait until after the threat subsides. However, in someone with an anxiety disorder, where there is constant activation of these responses to everyday stressors, the stress hormone system loses its ability to control immune function, thus contributing to heightened systemic inflammation that increases risk for cardiovascular and even autoimmune disorders. Neuroscience and clinical research continues to investigate how anxiety disorders increase individual risk for developing physical health co-morbidities in hopes of identifying new treatments that may alleviate suffering from and prevent the development of these whole-body disorders.
Agoraphobia is an anxiety disorder which primarily consists of the fear of experiencing a difficult or embarrassing situation from which the sufferer cannot escape. Panic attacks are commonly linked to agoraphobia and the fear of not being able to escape a bad situation.[20] As the result, severe sufferers of agoraphobia may become confined to their homes, experiencing difficulty traveling from this "safe place".[21] The word "agoraphobia" is an English adoption of the Greek words agora (αγορά) and phobos (φόβος). The term "agora" refers to the place where ancient Greeks used to gather and talk about issues of the city, so it basically applies to any or all public places; however the essence of agoraphobia is a fear of panic attacks especially if they occur in public as the victim may feel like he or she has no escape. In the case of agoraphobia caused by social phobia or social anxiety, sufferers may be very embarrassed by having a panic attack publicly in the first place. This translation is the reason for the common misconception that agoraphobia is a fear of open spaces, and is not clinically accurate. Agoraphobia, as described in this manner, is actually a symptom professionals check for when making a diagnosis of panic disorder.

Guided imagery is another relaxation strategy that can help reduce or prevent overwhelming anxiety. Guided imagery involves directed mental visualization to evoke relaxation. This could involve imagining your favorite beach or a peaceful garden that can distract you from your anxious state and allow your mind and body to focus on the positive thoughts and sensations of the imagery exercise.

Almost everyone experiencing symptoms of a panic attack needs evaluation. Unless the person has a history of having panic attacks, is otherwise healthy, and is experiencing a typical attack, they must be evaluated promptly by a doctor. The level of evaluation depends on many factors. Err on the side of safety when deciding whether to go to a hospital's emergency department.
As with most behavioral illnesses, the causes of panic attacks are many. Certainly there is evidence that the tendency to have panic attacks can sometimes be inherited. However, there is also evidence that panic may be a learned response and that the attacks can be initiated in otherwise healthy people simply given the right set of circumstances. Research into the causes of panic attacks is ongoing.

Characterized by a suite of symptoms that persist for at least three days and up to one month after a traumatic experience (same diagnostic criteria for "trauma" as listed above). The specific symptoms of the disorder vary across individuals, but a common feature is intense anxiety in response to re-experiencing symptoms (e.g., recurrent intrusive recollections of traumatic event) of the trauma.
“Anxiety attack” is not a formal, clinical term, but one that is used by many people to describe all sorts of things, from feeling worried about an upcoming event to intense feelings of terror or fear that would meet the diagnostic criteria for a panic attack. In order to understand what someone means by “anxiety attack,” it is necessary to consider the context in which the symptoms occur.
Anxiety attacks usually peak within 10 minutes, and they rarely last more than 30 minutes. But during that short time, the terror can be so severe that you feel as if you’re about to die or totally lose control. The physical symptoms of anxiety attacks are themselves so frightening that many people believe they’re having a heart attack. After an anxiety attack is over, you may be worried about having another one, particularly in a public place where help isn’t available or you can’t easily escape.
The buildup phase of a panic attack is the most important phase, because it is when you can prevent it. If you are under chronic stress, you become worn down and have no reserve left. Anything can push you over the edge. But if you regularly reduce your stress through a combination of cognitive behavioral therapy and mind-body relaxation, you will have enough reserve left to handle life’s surprises.
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.