I nearly passed out at work today and the thing is I have no idea why.

I was adequately hydrated, I ate a decent lunch, I wasn't having any caffeine or anything sugar laden. I was talking to a coworker and lost my vision for a split second, felt wobbly and it felt like my body was starting to lean to the side. I felt like I was about to go down. I regained control and prevented that from happening but it was the weirdest feeling.