Panic disorders tend to run in families and many researchers believe that biochemical factors may play a crucial role with this condition. It is a fairly common disorder, found in 1 to 2% of the population. But, because so many of the symptoms of a panic attack resemble those of an organic disorder, people often fail to recognize them and end up visiting physicians in the mistaken belief that they have cardiac or respiratory problems.

Panic disorders run in my family on my father's side. It started with my grandfather, then my uncle and father, and now my two cousins have them. Each of us experienced different types of physical symptoms, but, for the most part, the symptoms consist of: Shortness of breath, or smothering sensations, dizziness, unsteady feelings, or faintness, palpitations or accelerated heart rate, trembling or shaking, numbness or tingling sensations usually in the fingers, toes, or lips, flushes or chills, chest pain or discomfort, fear of becoming seriously ill or dying, fear of going crazy or doing something uncontrolled, sweating, choking, nausea or abdominal distress, and feelings of unreality.

People who say that "anxiety is all in your head" simply are not very observant. Anyone who has experienced severe anxiety knows it can involve virtually the entire body.

In his book "The Psychology of Fear and Stress" Psychologist Jeffrey Gray explains the "emergency reaction". According to Gray, the emergency reaction serves a vital role in protecting us from harm:

"It's function is to mobilize the body's resources for swift action - "fight or flight" - that may be needed. There is an increase in the rate and strength of the heart beat, allowing oxygen to be pumped round more rapidly; contraction of the spleen, releasing stored red blood cells to carry this oxygen; release of stored sugar from the liver for the use of the muscles; redistribution of the blood supply from the skin and viscera to the muscles and brain; deepening of respiration and dilation of the bronchi, to take in more oxygen; dilation of the pupils, perhaps to improve visual efficiency; an increase in the blood's ability to seal wounds by coagulating; and a rise in the supply of the special blood cells known as "lymphocytes", whose function is to help repair damage to the tissue. All of this takes place in a matter of seconds or minutes".