[1] Panic attacks are sudden periods of intense fear that may include palpitations, sweating, shaking, shortness of breath, numbness, or a feeling that something terrible is going to happen.

[3] Diagnosis involves ruling out other potential causes of anxiety including other mental disorders, medical conditions such as heart disease or hyperthyroidism, and drug use.

Other symptoms are a sensation of choking, paralysis, chest pain, nausea, numbness or tingling, chills or hot flashes, vision problems, faintness, crying[10] and some sense of altered reality.

Smoking cigarettes may lead to panic attacks by causing changes in respiratory function (e.g. feeling short of breath).

Nicotine and other psychoactive compounds with antidepressant properties in tobacco smoke which act as monoamine oxidase inhibitors in the brain can alter mood and have a calming effect, depending on dose.

A number of clinical studies have shown a positive association between caffeine ingestion and panic disorder and/or anxiogenic effects.

[44] Most stimulant drugs (caffeine, nicotine, cocaine) would be expected to worsen the condition, since they directly increase the symptoms of panic, such as heart rate.

The authors found that compared to healthy controls, sedative use was greater for non-clinical participants who experienced panic attacks.

These findings are consistent with the suggestion made by Cox, Norton, Dorward, and Fergusson (1989)[46] that panic disorder patients self-medicate if they believe that certain substances will be successful in alleviating their symptoms.

[48] The reason chronic alcohol misuse worsens panic disorder is due to distortion of the brain chemistry and function.

[49][50][51] Approximately 10% of patients will experience notable protracted withdrawal symptoms, which can include panic disorder, after discontinuation of benzodiazepines.

Someone experiencing the toxic effects of recreational alcohol use or chronic sedative use will not benefit from other therapies or medications for underlying psychiatric conditions as they do not address the root cause of the symptoms.

Some studies have looked at theories suggesting a chronic state of hyperventilation and other carbon dioxide receptor hypersensitivity could represent genetic causes for panic disorder.

During acute panic attacks, viewing emotionally charged words, and rest, most studies find elevated blood flow or metabolism.

Rodent and human studies heavily implicate the periaqueductal grey in generating fear responses, and abnormalities related to the structure and metabolism in the PAG have been reported in panic disorder.

Elevated ventral ACC and dorsolateral prefrontal cortex during symptom provocation and viewing emotional stimuli have also been reported, although findings are not consistent.

The reduced production of GABA-A sends false information to the amygdala which regulates the body's "fight or flight" response mechanism and, in return, produces the physiological symptoms that lead to the disorder.

One such mediator is the partial pressure of carbon dioxide, which mediates the relationship between panic disorder patients receiving breathing training and anxiety sensitivity; thus, breathing training affects the partial pressure of carbon dioxide in a patient's arterial blood, which in turn lowers anxiety sensitivity.

[65] The ICD-10 diagnostic criteria: The essential feature is recurrent attacks of severe anxiety (panic), which are not restricted to any particular situation or set of circumstances and are therefore unpredictable.

[75][76][77] A number of randomized clinical trials have shown that CBT achieves reported panic-free status in 70–90% of patients about 2 years after treatment.

The underlying theory posits that due to biochemical vulnerability, traumatic early experiences, or both, people with panic disorder have a fearful dependence on others for their sense of security, which leads to separation anxiety and defensive anger.

[79] Comparative clinical studies suggest that muscle relaxation techniques and breathing exercises are not efficacious in reducing panic attacks.

These findings lend credibility to the application of CBT programs to patients who are unable to access therapeutic services due to financial, or geographic inaccessibility.

[83] Koszycky et al. (2011) discuss the efficacy of self-administered cognitive behavioural therapy (SCBT) in situations where patients are unable to retain the services of a therapist.

[89] A systematic analysis of trials testing this kind of self-help found that websites, books, and other materials based on cognitive-behavioral therapy could help some people.

Selective serotonin reuptake inhibitors are first line treatments rather than benzodiazapines due to concerns with the latter regarding tolerance, dependence and abuse.

Women are twice as likely as men to develop panic disorder[106] and it occurs far more frequently in people of above average intelligence [citation needed].

If left untreated, it may worsen to the point where one's life is seriously affected by panic attacks and by attempts to avoid or conceal the condition.

Consistent with this previous work, Diler et al. (2004) found similar results in their study in which 42 youths with juvenile panic disorder were examined.

Like adults, children experience physical symptoms including accelerated heart rate, sweating, trembling or shaking, shortness of breath, nausea or abdominal pain, dizziness or light-headedness.