What Causes Fainting And Dizziness?

When i was 17 i started having fainting spells...they would come on real quick with dizziness, nausea, and feeling like someone turned the thermostat up in my body! I was diagnosed then with what they called Near Syncope and was told it would go away with age. Sure enough after the age of 19 it disapeared almost as quickly as it started. Now at the age of 26 its like it s back with a vengence only worse. I say worse because i don t pass out. Passing out made it better because i didn t remember the almost agonizing dizziness and i was almost fine after waking except for being very fatigued. Now...if i don t eat almost immediately when i think i should or feel just the tiniest bit of hunger...i get this rush of feeling hot, dizzy, very weak, and trouble focusing. Normall eating would make this go away...but lately food has not come to my rescue. Unfortunately this has been happening every day for the last week and i m becoming very bothered by it and almost afraid to even get up in the morning. Help!