The other day I fainted on my way to work. I was reading the newspaper waiting for the train to come. All of sudden I felt nauseous and then like I was going to faint - my heart was beating fast, I was sweating, my vision was going blurry. A few minuets later I woke up to my boyfriend and a stranger standing over me telling me I had fainted i've only fainted one other time in my life - and that was from sunstroke. This is definitely not the case this time - as it's the middle of winter! I'm racking my brain trying to figure out what would have caused me to faint. On a seperate, but maybe not unrelated note - i've had irregular periods lately - despite being on the pill - missed a few months, had period spotting, etc.

I would be appreciative of any thoughts on what could have caused this fainting spell.