A headrush is a feeling of light-headedness. Headrushes usually happen if you stand up after sitting down for a long period of time. Your field of vision shrinks temporarily, and it looks like you're
blacking out, but it only makes you dizzy for a few seconds until the feeling wears off.
Headrushes can cause some
embarrassment, because they occur on a slight delay, so that you're already far from your chair when the feeling kicks in. If there's a table or wall nearby, lean on it for support
just in case. Otherwise, just sit down or stand there for a few seconds.
If you are prone to skip meals some days, or don't get enough sleep, you are more likely to get headrushes. Frequent headrushes are crazy as hell, but get old pretty quickly.
"John usually skips
breakfast, but he pulled an all-nighter and missed lunch today. Poor bastard got a headrush on his way to Biology and fell over in the hall."
"Whoa, dude, I just headrushed like crazy. I need to
stop playing TFT for a while,
I've been on for like three hours."