An anxiety attack, or panic attack varies from person to person in terms of
symptoms and severity. For most though it is a scary experience and it is
important to recognise what's going on during the attack and acknowledge that
its not as bad as it seems.
It should be noted that we're all different biologically and so we should expect
our bodies to have different symptoms. If you have more that the brief summary
below or if you don't get some of them this does not mean you have a worse
condition or anything.
The most common symptoms are shortness of breath, tightening sensation in the
chest, usually increased in heart rate although some people's heart beat
decreases and a feeling of fear or even impending doom.
They can come on at any time and for no apparent reason. Its important to
remember during the attack that the symptoms you're experiencing, although very
scary, are not going to harm you in any way. The symptoms are mostly brought on
by fear with the body going in to 'fight or flight' more.
 As we're all different, it can be sometimes difficult to answer the
question, 'What does an anxiety attack feel like?' Adrenaline is released in the
body and this has a number of effects in the body, such as raising heart rate
and sweating. The beating of the heart can sometimes feel extreme.
An anxiety attack is quite scary in most cases and is made even more scary by
the reactions of the body such as racing heart, chest tightness etc. These
symptoms are caused by the body in its preparation for 'fight or flight' mode
and are harmless.
A lot of people say the sensation feels like they're having a heart attack or
they're going to suffocate. Both sensations are the body exaggerating whats
actually going on and in reality there is no danger to the person.

Break The Fear Of Having Another Panic Attack :
http://groups.yahoo.com/group/panicpml/