Moreover, this hypocapnia and release of adrenaline during a panic attack cause vasoconstriction resulting in slightly less blood flow to the head which causes dizziness and lightheadedness. A panic attack can cause blood sugar to be drawn away from the brain and toward the major muscles. Neuroimaging suggests heightened activity in the amygdala, thalamus, hypothalamus, and brainstem regions including the periaqueductal gray, parabrachial nucleus, and Locus coeruleus. In particular, the amygdala has been suggested to have a critical role. The combination of high arousal in the amygdala and brainstem along with decreased blood flow and blood sugar in the brain can lead to dramatically decreased activity in the prefrontal cortex region of the brain. There is evidence that having an anxiety disorder increases the risk of cardiovascular disease (CVD). Those affected also have a reduction in heart rate variability.
Anxiety is typified by exaggerated worries and expectations of negative outcomes in unknown situations, and such concerns are often accompanied by physical symptoms. These include muscle tension, headaches, stomach cramps, and frequent urination. Behavioral therapies, with or without medication to control symptoms, have proved highly effective against anxiety, especially in children.
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.
Panic disorder involves repeated episodes of sudden feelings of intense anxiety and fear or terror that reach a peak within minutes (panic attacks). You may have feelings of impending doom, shortness of breath, chest pain, or a rapid, fluttering or pounding heart (heart palpitations). These panic attacks may lead to worrying about them happening again or avoiding situations in which they've occurred.
Generally, anxiety arises first, often during childhood. Evidence suggests that both biology and environment can contribute to the disorder. Some people may have a genetic predisposition to anxiety; however, even so, development of the condition is not inevitable. Early traumatic experiences can also reset the body’s normal fear-processing system so that it is hyper-reactive.
Comorbidity is more common than not with anxiety disorders, meaning that most individuals who experience significant anxiety experience multiple different types of anxiety. Given this co-morbidity, it is not surprising that many risk factors are shared across anxiety disorders, or have the same underlying causes. There is a lot of research identifying risk factors for anxiety disorders, and this research suggests that both nature and nurture are very relevant. It is important to note that no single risk factor is definitive - many people may have a risk factor for a disorder, and not ever develop that disorder. However, it is helpful for research to identify risk factors and for people to be aware of them, as being aware of who might be at risk can potentially help people get support or assistance in order to prevent the development of a disorder.
Anxiety disorders respond very well to therapy—and often in a relatively short amount of time. The specific treatment approach depends on the type of anxiety disorder and its severity. But in general, most anxiety disorders are treated with therapy, medication, or some combination of the two. Cognitive-behavioral therapy and exposure therapy are types of behavioral therapy, meaning they focus on behavior rather than on underlying psychological conflicts or issues from the past. They can help with issues such as panic attacks, generalized anxiety, and phobias.
Anyone who’s ever had a panic attack can tell you what a rollercoaster-of-a-ride it can be. It comes on suddenly, gripping its victims in extreme fear and heart-thumping, breathtaking physical distress. Minutes later, it’s over. When panic attacks occur repeatedly and people’s lives are gripped by fear of having the next panic episode, they may be diagnosed with panic disorder.
The cognitive effects of anxiety may include thoughts about suspected dangers, such as fear of dying. "You may ... fear that the chest pains are a deadly heart attack or that the shooting pains in your head are the result of a tumor or an aneurysm. You feel an intense fear when you think of dying, or you may think of it more often than normal, or can't get it out of your mind."
People who have panic attacks typically spend a lot of time worrying about having more attacks and often make seemingly unreasonable lifestyle changes in an attempt to avoid circumstances that will trigger future attacks. They may avoid situations that, they feel, have precipitated previous episodes or environments where they would not be able to escape easily if another attack should occur.
Furthermore, certain organic diseases may present with anxiety or symptoms that mimic anxiety. These disorders include certain endocrine diseases (hypo- and hyperthyroidism, hyperprolactinemia), metabolic disorders (diabetes), deficiency states (low levels of vitamin D, B2, B12, folic acid), gastrointestinal diseases (celiac disease, non-celiac gluten sensitivity, inflammatory bowel disease), heart diseases, blood diseases (anemia), cerebral vascular accidents (transient ischemic attack, stroke), and brain degenerative diseases (Parkinson's disease, dementia, multiple sclerosis, Huntington's disease), among others.
If you, or someone you know, has symptoms of anxiety disorder, visit a clinician, who can help determine whether the symptoms are due to an anxiety disorder, medical condition or both. Frequently, the next step in getting treatment for an anxiety disorder is referral to a mental health professional such as a psychiatrist, psychologist, social worker or counselor.
Anxiety can be either a short-term 'state' or a long-term personality "trait". Trait anxiety reflects a stable tendency across the lifespan of responding with acute, state anxiety in the anticipation of threatening situations (whether they are actually deemed threatening or not). A meta-analysis showed that a high level of neuroticism is a risk factor for development of anxiety symptoms and disorders. Such anxiety may be conscious or unconscious.
Kirstie Craine Ruiz, 46, has lived with anxiety, panic attacks, and panic disorder for about ten years. For a long time, she had full-blown attacks 2-3 nights a week. “I would usually awake to a racing heart or the feeling of my heart expanding in my chest…like it might explode… From there, I would begin to panic and my heart would go even faster….and my body would shake so hard that it felt like I was having a convulsion. I could barely breathe and was usually pretty sure I was having a heart attack and that I was going to die. Sometimes I’d go the ER and they’d hold me overnight because my heart would be going so fast and they couldn’t get it to go down.”
The review, conducted by researchers at Cambridge University in England, also found that people with chronic health conditions were more likely to experience anxiety. According to the review, almost 11 percent of people with heart disease in Western countries reported having generalized anxiety disorder (GAD). In addition, 32 percent of those with multiple sclerosis had some kind of anxiety disorder. (3)
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. 
I’ve been having anxiety for like 3-4 weeks I’m having a serious medical condition , no matter how many doctors nurses or anyone tell me I’m okay I stay on google to make sure I don’t have symptoms then next thing you know I have every symptom in the book , one day is this and another is that …. I don’t know how to stop it because no matter what people are telling me I keep thinking they are wrong and I keep teeth clenching which is making my jaw hurt , I get stomach aches sometimes and I have to urinate a lot at night , my anxiety is so bad I can’t stay off google for longer that 5 minutes without looking anything up ….. I don’t know what to do anymore
More than shyness, this disorder causes intense fear about social interaction, often driven by irrational worries about humiliation (e.g. saying something stupid or not knowing what to say). Someone with social anxiety disorder may not take part in conversations, contribute to class discussions or offer their ideas, and may become isolated. Panic attacks are a common reaction to anticipated or forced social interaction.
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.