Panic attacks involve sudden feelings of terror that strike without warning. These episodes can occur at any time, even during sleep. People experiencing a panic attack may believe they are having a heart attack or they are dying or going crazy. The fear and terror that a person experiences during a panic attack are not in proportion to the true situation and may be unrelated to what is happening around them. Most people with panic attacks experience several of the following symptoms:
Simple Phobias and Agoraphobia: People with panic disorder often develop irrational fears of specific events or situations that they associate with the possibility of having a panic attack. Fear of heights and fear of crossing bridges are examples of simple phobias. As the frequency of panic attacks increases, the person often begins to avoid situations in which they fear another attack can occur or places where help would not be immediately available. This avoidance may eventually develop into agoraphobia, an inability to go beyond known and safe surroundings because of intense fear and anxiety. Generally, these fears can be resolved through repeated exposure to the dreaded situations, while practicing specific techniques to become less sensitive to them.
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. 
Many medical conditions can cause anxiety. This includes conditions that affect the ability to breathe, like COPD and asthma, and the difficulty in breathing that often occurs near death. Conditions that cause abdominal pain or chest pain can cause anxiety and may in some cases be a somatization of anxiety; the same is true for some sexual dysfunctions. Conditions that affect the face or the skin can cause social anxiety especially among adolescents, and developmental disabilities often lead to social anxiety for children as well. Life-threatening conditions like cancer also cause anxiety.
If you think a friend or colleague at work is experiencing an anxiety disorder or other mental health difficulty, you should carefully consider how you react. Your actions in the workplace can have work-related and legal consequences. However, intervening early before an emergency situation arises can help prevent greater consequences for your colleague's career, health, and safety.
When we experience an involuntary high degree stress response, the sensations can be so profound that we think we are having a medical emergency, which anxious personalities can react to with more fear. And when we become more afraid, the body is going to produce another stress response, which causes more changes, which we can react to with more fear, and so on.
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.
When used in the appropriate person with close monitoring, medications can be quite effective as part of treatment for panic disorder. However, as anything that is ingested carries a risk of side effects, it is important for the individual who has panic attacks to work closely with the prescribing health care professional to decide whether treatment with medications is an appropriate intervention and, if so, which medication should be administered. The person being treated should be closely monitored for the possibility of side effects that can vary from minor to severe, and in some cases, even be life-threatening. Due to the possible risks to the fetus of a mother being treated for panic attacks with medication, psychotherapy should be the first treatment tried when possible during pregnancy and the risk of medication treatment should be weighed against the risk of continued panic attacks in regard to the impact of a developing fetus.
Carbonell says that understanding the physiology of fainting and reminding yourself of it is important. People faint when their blood pressure drops. A anxiety attack can make you feel like you’re going to faint, but you won’t because your blood pressure doesn't drop during an attack. Remind yourself out loud of truths like these to counter your fears.
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).
Some benefits of benzodiazepines are that they are effective in relieving anxiety and take effect more quickly than antidepressant medications often prescribed for anxiety. Some drawbacks of benzodiazepines are that people can build up a tolerance to them if they are taken over a long period of time and they may need higher and higher doses to get the same effect. Some people may even become dependent on them.