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]
If left untreated, anxiety may worsen to the point at which the person's life is seriously affected by panic attacks and by attempts to avoid or conceal them. In fact, many people have had problems with friends and family, failed in school, and/or lost jobs while struggling to cope with this condition. There may be periods of spontaneous improvement in the episodes, but panic attacks do not usually go away unless the person receives treatments designed specifically to help people with these symptoms.
Panic disorder is thought to have a psychobiological conceptualization (Craske & Barlow, 2007). This does not mean that panic attacks are due to a biological disease. What this does mean is that there are certain biological factors that may be inherited or passed on through genes, and thus may lead some people to be more likely than others to experience panic disorder symptoms. This is likely why panic disorder seems to run in families. In other words, if one family member has panic disorder, the other family members are more likely to experience panic symptoms or panic disorder compared to people without a family history of panic disorder. It is very important to note that just inheriting these vulnerabilities to panic does not make the onset of panic attacks inevitable or unalterable. In fact, it is possible to think and act in ways that prevent panic attacks.
All human beings experience anxiety. In many cases, anxiety can have some beneficial and adaptive qualities such as pushing one to study for an upcoming difficult exam or propelling a person to flee from danger. Although experiencing some anxiety with life stressors and worries is normal, sometimes it can be difficult to manage and can feel overwhelming. Below we provide a list of tips and strategies to help individuals prevent anxiety from reaching a diagnosable level. Even though not everyone will struggle with a diagnosable anxiety disorder, learning strategies to aid in relief from anxiety and to manage the "normal" anxiety experienced in everyday life can help you live the life you desire.
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:

Selective mutism: A somewhat rare disorder associated with anxiety is selective mutism. Selective mutism occurs when people fail to speak in specific social situations despite having normal language skills. Selective mutism usually occurs before the age of 5 and is often associated with extreme shyness, fear of social embarrassment, compulsive traits, withdrawal, clinging behavior, and temper tantrums. People diagnosed with selective mutism are often also diagnosed with other anxiety disorders.