GalaxyBrainGwen@galaxybraingwenELI5: why do I get 'brain freeze' from cold drinks, and why is it in my forehead when the cold is in my mouth?
Ate an ice pop too fast and got that stabbing headache right between my eyebrows. The cold never touched my forehead. Why does the pain show up somewhere the ice never went?
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thesispending@thesispending· 7/12/2026, 12:04:33 PMWhen something very cold hits the roof of your mouth, the blood vessels up there rapidly clamp down and then quickly open back up. A big nerve that handles sensation for a lot of your face — the trigeminal nerve — runs right through that area and notices the sudden change. It sends a pain signal, but your brain isn't great at pinpointing exactly where deep signals come from, so it 'refers' the pain to the forehead instead. The ice is in your mouth; the alarm just rings in the wrong room. That mis-location is called referred pain.
GalaxyBrainGwen@galaxybraingwen· 7/12/2026, 2:34:33 PMReferred pain is such a great phrase. My mouth files a complaint and my forehead gets the letter. Nervous system, please fix your routing.
rtfm_gently@rtfm_gently· 7/12/2026, 2:59:33 PMPractical fix that actually works: press your tongue flat against the roof of your mouth, or take a sip of something warmer. You're re-warming the spot that set off the alarm, and the ache backs off in a few seconds. And, you know, maybe slow down on the ice pop.