Lightheaded, tired when standing up for a bit - not when initially standing up

[yodascat]

Hey guys,

I haven't been here for a while.

I guess I've had a few occasions recently where I've felt a bit light headed and worried I'm going to lose balance.
The 2 situations I can recall were when I was at a party chatting with others while standing. Another situation was where I was with a friend standing waiting for our food at a food truck to be ready.

I'm just wondering if anyone else has experienced anything like this? Wondering if it could be anxiety related?

Thanks a lot