These physiological responses can actually help us to survive. However, sometimes we experience these physiological responses, like an increased heartbeat, that are not in the presence of danger at all, but something else entirely. In these cases, our bodies can misinterpret these physiological signals as being indicators of danger or a "true threat." For example, people may experience learned anxiety due to previous associations between elevated heart rate and panic attacks and may misinterpret bodily sensations as signs of imminent death or loss of control. In this way, one may start to fear these physiological responses, which is what we call "fear of fear" (Craske & Barlow, 2007). "Fear of fear" maintains or perpetuates panic attacks and panic symptoms, which becomes a vicious cycle. In other words, you experience an increased heart rate, which you interpret as negative, which makes you feel anxious, which further makes your heart rate increase and it often spirals from there. These associations may almost happen automatically, even without conscious thought, but this is what is likely going on behind the scenes.

"These techniques take some getting used to,” says Dave Carbonell, PhD, an anxiety therapist in Chicago, but learning how to cope with anxiety attacks is important so that fear of having another won't keep you at home or limit your activities. A study in Alternative Therapies in Health and Medicine in 2013 found that multiple approaches to managing anxiety, including strategies like breathing and journaling, can help. 
We all experience anxiety. For example, speaking in front of a group can make us anxious, but that anxiety also motivates us to prepare and practice. Driving in heavy traffic is another common source of anxiety, but it helps keep us alert and cautious to avoid accidents. However, when feelings of intense fear and distress become overwhelming and prevent us from doing everyday activities, an anxiety disorder may be the cause.
Heredity, other biological factors, stressful life events, and thinking in a way that exaggerates relatively normal bodily reactions are all believed to play a role in the onset of panic disorder. Some research suggests panic attacks occur when a “suffocation alarm mechanism” in the brain is activated, falsely reporting that death is imminent. The exact cause or causes of panic disorder are unknown and are the subject of intense scientific investigation.
When people are confronted with unpleasant and potentially harmful stimuli such as foul odors or tastes, PET-scans show increased bloodflow in the amygdala.[87][88] In these studies, the participants also reported moderate anxiety. This might indicate that anxiety is a protective mechanism designed to prevent the organism from engaging in potentially harmful behaviors.

Everyone here has issues, but what happens when you’re blue as hell and CANNOT figure out the source of the problem? There is no quote, no book, no video, no saying or phrase, no motto, which is helping me right now. I feel like absolute total HELL. And I damned well know it’s not going to last, and that it’s probably a result of thinking too hard, too long, too deeply. Anyway, thank you all for sharing your pain with strangers. It shows that you’re way stronger than you think.
When people are confronted with unpleasant and potentially harmful stimuli such as foul odors or tastes, PET-scans show increased bloodflow in the amygdala.[87][88] In these studies, the participants also reported moderate anxiety. This might indicate that anxiety is a protective mechanism designed to prevent the organism from engaging in potentially harmful behaviors.
I’m 15 years old and this is something very similar that happens to me everyday, it sneaks up on me at random times. It is a terrible feeling and almost uncontrollable. It started around 5 months ago when my grandfather passed away, I went to the the hospital atleast 5 times and I even get suicidal thoughts sometimes because the feeling is terrible and something I don’t wanna go through everyday. I don’t know what to do.
Signs of mental health difficulty can be different in the workplace than in other settings. The Harvard Mental Health Letter outlines signs that you may notice in your co-workers, which could indicate a significant problem. For anxiety disorders, these can include restlessness, fatigue, difficulty concentrating, excess worrying, and a general impairment in quality of work.
There are long-term, biological, environmental, and social causes of panic attacks. In 1993, Fava et al. proposed a staging method of understanding the origins of disorders. The first stage in developing a disorder involves predisposing factors, such as genetics, personality, and a lack of wellbeing.[11] Panic disorder often occurs in early adulthood, although it may appear at any age. It occurs more frequently in women and more often in people with above-average intelligence. Various twin studies where one identical twin has an anxiety disorder have reported a 31–88% incidence of the other twin also having an anxiety disorder diagnosis.[12]
Panic disorder affects 2-3% of people every year in the United States and Europe, with varying rates depending on race and ethnicity. On average, Native American Indian populations experience panic disorder at higher rates than non-Latino white Americans. In contrast, African Americans, Latinos, Caribbean Blacks, and Asian Americans all experience the disorder at lower rates than non-Latino white Americans. In addition, it has been well established than females are twice as likely to be diagnosed with panic disorder than males (Asnaani, Gutner, Hinton, & Hofmann, 2009; McLean, Asnaani, Litz, & Hofmann, 2011). A number of factors (e.g., biological influences, temperament, exposure to stressors and trauma, cognitive factors, and environmental factors) have been identified as possibly influencing sex differences in rates of panic disorder (McLean & Anderson, 2009). However, no one theory has been determined so the underlying reason for sex differences in rates of panic disorder remains unknown.

In people with anxiety disorders, the brain circuitry that controls the threat response goes awry. At the heart of the circuit is the amygdala, a structure that flags incoming signals as worrisome and communicates with other parts of the brain to put the body on alert for danger. Early life events, especially traumatic ones, can program the circuitry so that it is oversensitive and sends out alarms too frequently and with only minor provocations. Survival mandates a system for perceiving threats and taking quick, automatic action, but those with anxiety see threats where there are none, perhaps because emotional memories color their perceptions.

Prevention is more effective than treatment for panic attacks. Prevention involves stress management methods such as meditation and mindfulness to reduce your stress so that it doesn’t accumulate and eventually erupt into a panic attack. Prevention is not about stopping a panic attack just before it happens. The best you can do just before a panic attack is manage it.
Anxiety is distinguished from fear, which is an appropriate cognitive and emotional response to a perceived threat.[12] Anxiety is related to the specific behaviors of fight-or-flight responses, defensive behavior or escape. It occurs in situations only perceived as uncontrollable or unavoidable, but not realistically so.[13] David Barlow defines anxiety as "a future-oriented mood state in which one is not ready or prepared to attempt to cope with upcoming negative events,"[14] and that it is a distinction between future and present dangers which divides anxiety and fear. Another description of anxiety is agony, dread, terror, or even apprehension.[15] In positive psychology, anxiety is described as the mental state that results from a difficult challenge for which the subject has insufficient coping skills.[16]
Not getting enough restful sleep can trigger anxiety. Stress and anxiety can also interfere with sleep and cause you to stay awake at night. It can be a frustrating cycle when the stressors of the day and future worries cause you stay up at night. Take some time to wind down before bed such as utilizing some of the above relaxation and meditation strategies. Also, instead of letting your mind continuously race at night, try putting your thoughts, worries, and plans for the next day on paper before bed. This will ease your anxiety about forgetting something you need to accomplish in the future and allow you to relax and rest.
Palpitations are uncomfortable sensations of the heart beating hard, rapidly, or irregularly. Some types of palpitations are benign, while others are more serious. Palpitations are diagnosed by taking the patient history and by performing an EKG or heart monitoring along with blood tests. An electrophysiology study may also be performed. Treatment of palpitations may include lifestyle changes, medication, ablation, or implantation of a pacemaker. The prognosis if palpitations depends on the underlying cause.
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.