Thanks for your query,
In most probability it was a vasovagal attack. A vasovagal attack itself is not serious; however, injury
is possible during a fainting
episode. Prolonged standing is associated with vasovagal attacks because blood may pool in the legs, thus reducing blood flow to the brain. You may be able to lower your risk of vasovagal attacks by lying down and elevating your feet if a vasovagal attack is beginning and understanding the potential triggers for vasovagal attacks.
Best of luck and take care..
Hope it helps..