Brain freeze, also known as an ice-cream headache or cold-stimulus headache has the very long scientific name of sphenopalatine ganglioneuralgia. It is a kind of short-term headache typically linked to the rapid consumption of ice-cream, ice pops, or very cold drinks.
A cold sensation in the mouth can lead to pain in the head. While brain freeze describes the feeling, it’s wrong, as the brain doesn’t have any pain receptors of its own. So why does a cold sensation in the mouth lead to pain in the head?
The long trigeminal nerve picks up sensations from the mouth, nose, teeth and forehead. A sudden chill causes blood vessels in the roof of the mouth to constrict and dilate, sending pain signals through the trigeminal nerve to the brain.
But this pain is felt in the forehead instead of the mouth. This could be because the forehead is more exposed to the outside world, so the brain assumes the signal is coming from there instead. This phenomenon is known as ‘referred pain’, and is also seen in heart attacks, when pain is felt in the shoulders or back. Luckily ‘brain freeze’ only lasts a few seconds and can be easily ended by swallowing quickly – at least until your next bite.
Illustration: Lauren Mortimer