A type of anxiety disorder, panic disorder causes the patient to have "repeated, unexpected attacks of intense fear," according to the experts at the National Institutes of Health (NIH). Women are twice as likely to be diagnosed with panic disorder, with symptoms starting before the age of 25. What causes panic disorder is not fully known, though certain factors, like stress, genetic and an abnormal fight-or-flight response, can contribute to its onset.
Stress
According to the Mayo Clinic, an incredibly stressful event may trigger the first panic attack of the panic disorder. For example, a patient may have an important presentation coming up, and the anticipation can cause an anxiety reaction: chest pain, nausea, trembling and palpitations for a period of 10 minutes, though the time can vary. After the initial anxiety attack, the patient can start having panic reactions before another presentation or stressful event. The patient might also experience symptoms from fear of another panic attack.
Genetics
Like other anxiety disorders, panic disorder has a genetic link. Panic disorder tends to run in families, and a person has a higher risk if a blood relative is also diagnosed with panic disorder or another anxiety disorder. The NIH notes that a person has a 40 percent risk of developing panic disorder if her identical twin also has the disorder. Since the risk is not 100 percent, other factors are involved in the development of the disorder.
Abnormal Fight-or-Flight Response
During a stressful event, a person's body reacts with the fight-or-flight response. The sympathetic nervous system, which is part of the autonomic nervous system, activates when the person is faced with an impending danger, resulting in the symptoms of anxiety. Once the stress is over, the parasympathetic nervous system, also part of the autonomic nervous system, reacts and returns the body to normal. A patient with a panic disorder, however, has an activation of the sympathetic nervous system even when no danger is present.
