While everyone experiences brief episodes of intense anxiety from time to time, and a great many people experience one or two anxiety attacks over the course of their lifetime, anxiety attack disorder occurs when these attacks become frequent or persistent, begin interfering with or restricting normal lifestyle, or when the individual becomes afraid of them. Once established, anxiety attack disorder can be very debilitating.
In order to manage threatening situations, humans have evolved to experience a "fight or flight" response. As part of this response, when humans are confronted with a dangerous situation, their body mobilizes by sending blood away from their extremities (e.g. hands and feet) and into the major muscles, producing adrenaline, and increasing heart rate so that we are better equipped to fight off danger.
The condition of steady, pervasive anxiety is called Generalized Anxiety Disorder. Yet there are numerous anxiety-related disorders. One is panic disorder—severe episodes of anxiety that occur in response to specific triggers. Another is obsessive-compulsive disorder, marked by persistent intrusive thoughts or compulsions to carry out specific behaviors, such as hand-washing. Post-traumatic stress disorder may develop after exposure to a terrifying event in which severe physical harm occurred or was threatened. Anxiety so frequently co-occurs with depression that the two are thought to be twin faces of one disorder. Like depression, anxiety strikes twice as many adult females as males.
Anxiety disorders are characterized by a general feature of excessive fear (i.e. emotional response to perceived or real threat) and/or anxiety (i.e. worrying about a future threat) and can have negative behavioral and emotional consequences. Obsessive-compulsive and related disorders are characterized by obsessive, intrusive thoughts (e.g., constantly worrying about staying clean, or about one's body size) that trigger related, compulsive behaviors (e.g. repeated hand-washing, or excessive exercise). These behaviors are performed to alleviate the anxiety associated with the obsessive thoughts. Trauma- and stressor- related anxiety disorders are related to the experience of a trauma (e.g., unexpected death of a loved one, a car accident, or a violent incident) or stressor (e.g., divorce, beginning college, moving).

Chest pain is always an alarming symptom, because most of us (appropriately) associate it with cardiac conditions, in particular  angina or a myocardial infarction (heart attack). However, chest pain can also be caused by a number of conditions that have nothing to do with the heart. And one of the more common non-cardiac problems that frequently produces chest pain is an anxiety attack.

Given that anxiety attacks aren’t specifically outlined as a diagnosis in the DSM-5, the usage of the word is open to interpretation and different individuals may use it in varying ways and circumstances. For one person, an anxiety attack might be overthinking about a specific worry to the extent that they are unable to concentrate on anything else; for another, anxiety attack might refer to sweating and shortness of breath when faced with a certain situation.
Anxiety is associated with abnormal patterns of activity in the brain. One way to treat anxiety is to directly target abnormal nerve cell activity. Neuromodulation or brain stimulation therapy is a non-invasive and painless therapy that stimulates the human brain. In some recent clinical trials, patients that did not respond to more traditional forms of treatment (i.e. medication) showed a reduction in symptoms of depression and anxiety. There are two main types of neuromodulation:
The problem with catastrophizing is that it is rigid thinking. Suppose you worry that you’re having a heart attack every time you experience some chest pain. It’s usually easy for a health professional to distinguish between anxiety and a heart attack. But catastrophizing resists new information. Even though, your doctor has done tests in the past and has reassured you many times, you worry that this time will be different. Your exaggerated fear is preventing you from changing your thinking, and is keeping you stuck.
People with generalized anxiety disorder (GAD) display excessive anxiety or worry, most days for at least 6 months, about a number of things such as personal health, work, social interactions, and everyday routine life circumstances. The fear and anxiety can cause significant problems in areas of their life, such as social interactions, school, and work.