What is vasovagal syncope and when does it happen?

Vasovagal Syndrome: It is a condition mediated by vagus nerve which leads to fainting or syncope..Itoccurs in responce to some triggerwhich causes heart rate to slow down, blood pressure drops, which causes lack of blood to the brain and it causes loss of consciousness.It is mediated throgh vagus nerve and sympathetic system.Triggers can be stress, pots.Venipuncture, sme drugs, ssris, violent coghing, hunger, lack of sleep, .