hi there, what you have described fits into the diagnosis of a vasovagal syncopal episode. There can be multiple causes for it but the most common are Prolonged standing or upright sitting Standing up very quickly (Orthostatic hypotension) Stress due to trauma Any painful or unpleasant stimuli, High pressure on or around the chest area after heavy exercise Myocardial infarction, Severe menstrual cramps Sudden onset of extreme emotions Lack of Sleep Dehydration Hunger Being exposed to high temperatures Pressing upon certain places on the throat, sinuses, and eyes (also known as vagal reflex) Use of certain drugs that affect blood pressure, such as cocaine, alcohol, marijuana, inhalants and opiate The sight of blood or blood drawing Violent coughing Low Blood Sugar,etc In an event of a vasovagal syncope one should not try to get up and the first aid given is to make the person in a lie down wlth the lower limb elevated above the level of the head.Sprinkle some cold water and massage the palm and feet. Any tight clothing should be loosened and he/she should be made to lie down in a well ventilated place or room. Take care.