Panic disorder is characterized by the spontaneous and unexpected occurrence of panic attacks, the frequency of which can vary from several attacks per day to only a few attacks per year. Panic attacks are defined as a period of intense fear in which 4 of 13 defined symptoms develop abruptly and peak rapidly less than 10 minutes from symptom onset. (See History.) Although such attacks can occur in other anxiety disorders, these attacks often occur without a discernible predictable precipitant in panic disorder. (See Diagnostic Considerations and Workup.)
To meet the Diagnostic and Statistical Manual of Mental Disorders,Fifth Edition (DSM-5)  criteria for panic disorder, panic attacks must be associated with longer than 1 month of subsequent persistent worry about: (1) having another attack or consequences of the attack, or (2) significant maladaptive behavioral changes related to the attack. To make the diagnosis of panic disorder, panic attacks cannot directly or physiologically result from substance use (intoxication or withdrawal), medical conditions, or another psychiatric disorder. (See History.) Other symptoms or signs may include headache, cold hands, diarrhea, insomnia, fatigue, intrusive thoughts, and ruminations. (See Physical Examination.)
Following exclusion of somatic disease, substance use disorders, and other psychiatric disorders, confirmation of the diagnosis of panic disorder with a brief mental status screening examination and initiation of appropriate treatment and referral is time- and cost-effective in patients with this condition, who have high rates of medical resource use. (See Mental Status Examination.)
Consequences of panic disorder
Panic disorder can lead to a significant hindrance in lifestyle. Individuals with panic disorder also may face problems with employment and depression. 
In addition, persons with panic disorder have a much higher risk of alcohol abuse or dependence and suicidality than the general population.  However, some studies suggest that panic disorder itself is not a risk factor for suicide in the absence of other risks, such as affective disorders, substance use disorders, eating disorders, and personality disorders.
DSM-5 criteria for panic disorder include 4 or more attacks in a 4-week period, or 1 or more attacks followed by at least 1 month of fear of another panic attack. 
The following are potential symptom manifestations of a panic attack  :
- Palpitations, pounding heart, or accelerated heart rate
- Trembling or shaking
- Sense of shortness of breath or smothering
- Feeling of choking
- Chest pain or discomfort
- Nausea or abdominal distress
- Feeling dizzy, unsteady, lightheaded, or faint
- Derealization or depersonalization (feeling detached from oneself)
- Fear of losing control or going crazy
- Fear of dying
- Numbness or tingling sensations
- Chills or hot flashes
During the episode, patients have the urge to flee or escape and have a sense of impending doom (as though they are dying from a heart attack or suffocation).
Patients with panic disorder have recurring episodes of panic, with the fear of recurrent attacks resulting in significant behavioral changes (e.g., avoiding certain situations or locations) and worry about the implications or consequences of the attack (e.g., losing control, going crazy, dying). Panic disorder may result in changes in personality traits, characterized by the patient becoming more passive, dependent, or withdrawn.
Types of panic attacks
Unexpected panic attacks have no known precipitating cue. Situationally-bound (cued) panic attacks recur predictably in temporal relationship to the trigger; these panic attacks usually implicate the diagnosis of a specific phobia. Situationally predisposed panic attacks are more likely to occur in relation to a given trigger, but they do not always occur.
A variant of panic disorder unrelated to fear (nonfearful panic disorder [NFPD]) is associated with high rates of medical resource use (32-41% of patients with panic disorder seeking treatment for chest pain) and a poor prognosis. 
Triggers of panic can include the following:
- Injury (e.g., accidents, surgery)
- Interpersonal conflict or loss
- Use of cannabis (can be associated with panic attacks  ; the associated anxiety/panic may be due to the direct physiologic effects of cannabis use)
- Use of stimulants, such as caffeine, decongestants, cocaine, and sympathomimetics (e.g., amphetamine, methylenedioxymethamphetamine [MDMA, ecstasy]) 
- The selective serotonin reuptake inhibitor (SSRI) discontinuation syndrome, which can induce symptoms similar to those experienced by panic patients
Assess precipitating events (e.g., major life events), phobias, agoraphobia, obsessive-compulsive behavior, and suicidal ideation and/or plan. In one study, lifetime rates of suicide attempts in patients with uncomplicated panic disorder were consistently higher (7%) than in individuals without a psychiatric disorder (1%). Also assess whether there is a family history of panic or other psychiatric illness.
Exclude involvement of alcohol, nicotine, illicit drugs (e.g., cocaine, amphetamine, phencyclidine, amyl nitrate, lysergic acid diethylamide [LSD], yohimbine, 3,4-methylenedioxymethamphetamine [MDMA, ecstasy]), cannabis, and medications (e.g., caffeine, theophylline, sympathomimetics, anticholinergics), including OTC agents.
In experimental settings, symptoms can be elicited in people with panic disorder by hyperventilation, inhalation of carbon dioxide,  caffeine consumption, or intravenous infusions of hypertonic sodium lactate or hypertonic saline, cholecystokinin, isoproterenol, flumazenil, or naltrexone.  The carbon dioxide inhalation challenge is especially provocative of panic symptoms in smokers.
All patients with panic disorder should be referred to a psychiatrist, psychologist, or other mental health professional. Psychiatric treatment has a demonstrated effect on decreasing medical costs associated with emergency department and nonpsychiatric outpatient care.  Free information is available to patients and physicians from the National Institute of Mental Health (NIMH) and the National Alliance on Mental Illness (NAMI) (which has a separate section on panic disorder that may be useful for patients and their families).
Pharmacotherapy, cognitive- behavioral therapy (CBT), and other psychological treatment modalities are used to manage panic disorder. The American Psychiatric Association (APA) recommends treating patients with panic disorder when symptoms cause dysfunction (e.g., work, family, social, leisure activities) or significant distress.  Treatment goals include the following  :
- Tailoring the treatment plan to each individual
- Reducing frequency and intensity of panic attacks
- Reducing anticipatory anxiety and agoraphobic avoidance
- Treating co-occurring psychiatric disorders
- Achieving full symptomatic remission
- Returning to premorbid level of function
Psychotherapy is recommended for patients with panic disorder who prefer nonpharmacologic management and who are able and willing to take the time and effort to participate in weekly (or sometimes alternate weekly) sessions and between-session practices.  The strongest available evidence is for CBT. [55, 56]
CBT, with or without pharmacotherapy, is the treatment of choice for panic disorder, and it should be considered for all patients.  This therapeutic modality has higher efficacy and lower cost, dropout rates, and relapse rates than do pharmacologic treatments. CBT may include countering anxious beliefs, exposure to fear cues, changing anxiety-maintaining behaviors, and preventing relapse. 
It is important to identify the frequency and nature of the panic disorder symptoms as well as the triggers of panic symptoms for effective management.  The patient’s symptomatic status should be monitored at each session, such as with the use of rating scales, and patients can also self-monitor by keeping a daily diary of panic symptoms.
Providing a few doses of a benzodiazepine as needed (prn) can enhance patient confidence and compliance. Limit the total tablet dispensation to ensure that patients understand that they have a limited supply of the drug and that this medicine represents a temporary or emergency use option.
Educate the patient regarding the importance of longer-term management with selective serotonin reuptake inhibitor (SSRI) medication and psychotherapeutic techniques (e.g., CBT). Avoid prescribing benzodiazepine in patients with a known history of substance misuse or alcoholism.
Inpatient vs outpatient care
Outpatient care is the general setting for uncomplicated panic disorder. Patients may be hospitalized if they display any evidence of dangerous behavior, have safety concerns, and/or report suicidal or homicidal ideation—as may occur in context of acute anxiety, fear of anxiety, or its consequences.
Considerations for admission include intoxication or withdrawal from sedative/hypnotics such as alcohol or alprazolam, which are sometimes ingested or abused in patients’ attempts to medicate or manage the anxiety. Patients may also be hospitalized if they become so incapacitated by their anxiety that they are unable to adhere to outpatient care. Inpatient treatment is also necessary in patients when the differential diagnosis includes other medical disorders that warrant admission (e.g., unstable angina, acute myocardial ischemia).
The APA recommends clinicians carefully assess the risk for suicide in patients with panic disorder as these individuals have an increased risk of suicidal ideation and behavior, regardless of whether comorbid conditions are present (e.g., major depression).