Panic Attack - Pathophysiology

Pathophysiology

While the various symptoms of a panic attack may cause the person to feel that their body is failing, it is in fact protecting itself from harm. The various symptoms of a panic attack can be understood as follows. First, there is frequently (but not always) the sudden onset of fear with little provoking stimulus. This leads to a release of adrenaline (epinephrine) which brings about the so-called fight-or-flight response wherein the person's body prepares for strenuous physical activity. This leads to an increased heart rate (tachycardia), rapid breathing (hyperventilation) which may be perceived as shortness of breath (dyspnea), and sweating (which increases grip and aids heat loss). Because strenuous activity rarely ensues, the hyperventilation leads to a drop in carbon dioxide levels in the lungs and then in the blood. This leads to shifts in blood pH (respiratory alkalosis or hypocapnia), which in turn can lead to many other symptoms, such as tingling or numbness, dizziness, burning and lightheadedness. Moreover, the release of adrenaline during a panic attack causes vasoconstriction resulting in slightly less blood flow to the head which causes dizziness and lightheadedness. A panic attack can cause blood sugar to be drawn away from the brain and towards the major muscles. It is also possible for the person experiencing such an attack to feel as though they are unable to catch their breath, and they begin to take deeper breaths, which also acts to decrease carbon dioxide levels in the blood.