1) Sensitivity to adrenalin and hormonal changes
In general, people with panic disorders including agoraphobia have overactive adrenal glands and are more likely to experience an adrenaline rush or "fight or flight" response when faced with a perceived psychological threat. This makes them more susceptible to panic attacks.
In panic disorder patients, adrenaline and a hormone called cortisol (a stress fighting hormone) are overproduced by the adrenal gland during times of prolonged stress.
The overproduction of adrenaline and cortisol interferes with the production of serotonin and dopamine. Serotonin and dopamine are neurotransmitters that stabilize your mood and sense of well-being. When serotonin and dopamine levels are low, your mood becomes unstable and you are less able to cope with stress.
In this state of chemical imbalance, you become more easily fatigued, your immune system is compromised, and you are more at risk for experiencing anxiety and panic attacks. Even after the original stressor is gone, you are likely to stay in a heightened state of anxiety.
2) Sensitivity to medications
A greater sensitivity to medications, including side effects, is observed among panic disorder patients. As mentioned previously, the side effects and/or withdrawal symptoms for some medications, including anti-anxiety medications, mimic the symptoms of anxiety and panic attacks. Because of this, medications prescribed to people who have panic attacks or panic disorder should be prescribed in smaller doses at first and then increased gradually as it is possible.
3) Sensitivity to physical stimulus
People who have panic attacks usually have a heightened sensitivity to bright lights, temperatures, sudden or harsh sounds, and other sources of physical stimulation. Physical stimulus will more easily overwhelm someone with panic disorder, create an aura of disorientation, and lead to a release of adrenaline (triggering the "fight or flight" response).
4) Sensitivity to large amounts of sodium lactate
Large amounts of sodium lactate in the bloodstream have been found by some researchers to cause panic attacks in people with panic disorder. Sodium lactate is produced when muscle cells convert sugar into energy. It is the basic solution in intravenous fluids given in the hospital.
In one study, panic disorder patients experienced a dramatic increase in blood flow to the temporal lobes of the brain when given sodium lactate. The temporal lobes are the same area of the brain affected when subjects in other studies (who do not have panic disorder) are given an electric shock!
