That is a good question! These were the results of the studies, I believe they are still trying to determine exactly why that is.
It is also interesting to note that the symptoms experienced by women typically differs from those experienced by men.
Both men and women list the most frequent symptom as heart pounding.
After this symptom there is a marked difference between women and men
in the symptoms reported. Women are much more likely to experience
respiration-related difficulties. That is, women report symptoms
including shortness of breath, feeling faint, feeling smothered and
nausea. Men on the other hand report symptoms including a sharp pain in
the stomach and sweating much more frequently than do women.
Not only are women more likely to develop on-going panic attacks but
women are more likely to have a more severe form of panic attacks that
include agoraphobia. Agoraphobia is commonly referred to as “fear of
the market place”. This means that panic attacks include the fear of
going to a public place or leaving one’s home. Women generally suffer
from agoraphobic fears more when they are alone than when they are with
another person.
But of course these findings, are saying that women are more likely. It does not mean that men do not experience the same.
http://www.selfgrowth.com/articles/panic-attacks-do-women-have-different-symptoms-from-men
Samantha, Health Educator