You’re enjoying a refreshing bowl of ice cream, and all of a sudden you experience a sharp, stabbing pain in your head. This common condition is known as an ice cream headache, or brain freeze.

Although scientists aren’t completely sure why this happens, there is one popular theory, which is explained in the PBS Digital Studios video below, hosted by Vanessa Hill.

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Medically, a brain freeze is known as "sphenopalatine ganglioneuralgia." In Latin, this means pain in the nerves around your face, sinuses, and the roof of your mouth.

When you eat ice cream quickly or slurp down a cold beverage, the blood flow in your nervous system is affected. As the ice cream hits the roof of your mouth, this sensation is picked up by nearby pain receptors. This burst of pain can sometimes be directly felt in your mouth where your blood vessels are being affected, but it most often feels like it’s in your actual brain.

The reason your brain experiences this is due to a phenomenon known as referred pain. Your pain signals become crossed and it feels like your pain is coming from your scalp, instead of mouth. Referred pain also explains why your left arm hurts when you have a heart attack.

Although brain freeze can cause short periods of discomfort, it’s not a serious medical issue, so there’s no reason to see a doctor. The next time you experience it, here’s some tips to ease the pain: press your tongue to the roof of your mouth, drink something warm after your cold beverage, or breath through your mouth and out your nose to pass warm air over your palate.

See also: 8 Weird Headache Causes: Hairstyles, Fragrances, Brain Freezes And Other Triggers You Didn’t Know

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