Thanks for the link Silverlady - it makes it all much clearer. So, basically, its not life threatening as long as it is not the cardiac type and means that the blood vessels in the legs shut down causing pooling which then leads to a fainting attack? Not serious but disconcerting non the less!
This part is interesting as my friend's mum recently fainted in the supermarket aisle and had to go to hospital even though she knew she had just not taken any notice of the warning signs she always gets
"Pay close attention to any prodromal symptoms. Syncope is usually preceded by at least a few seconds of symptoms that may consist of visual disturbances, buzzing in the ears, lightheadedness, sweating, nausea or other symptoms. Individuals who have had syncopal episodes usually have an excellent idea of what prodromal symptoms they should expect.
It is important to recognize these symptoms, because if you do, syncope can be averted almost 100% of the time by lying down and elevating your legs. On the other hand, if you choose to ignore the warning symptoms, you are likely to pass out in the frozen foods section of your supermarket, and the store manager will insist (for well-founded legal reasons) on shipping you to the E.R. in an ambulance, where you'll be subjected to a battery of unnecessary tests and probably an overnight stay in the hospital. Another advantage of avoiding the actual syncope by lying down is that when you do, you also avoid the prolonged period of feeling "sick" (wasted, washed out, nauseated and dizzy) that often follows a vasovagal episode."
Taz x