• How to explain that sharp sting from your ice-cold beverage (Flickr/by-2.0)
What's actually going on when your ice-cold drink gives you a piercing headache?
By
Kemal Atlay

28 Nov 2016 - 1:32 PM  UPDATED 28 Nov 2016 - 1:33 PM

Summer has arrived once again and with it brings the scorching heat that drives us to swimming pools, beaches and the ice-cream freezer in the supermarket.

It’s also the time of the dreaded 'brain freeze'.

Brain freeze has a couple of different names – ice-cream headache, cold-stimulus headache – but its scientific name is sphenopalatine ganglioneuralgia, which basically means 'nerve pain of the sphenopalatine ganglion'.

This nerve feeds into the roof of the mouth, also known as the hard palate, and hence is very closely placed to sense the cold from the ice-cream or slurpee you might be desperately devouring in an attempt to cool down to escape the heat.

Dr Brad McKay, a Sydney GP and host of Embarrassing Bodies Down Under, says this phenomenon is the body’s way of telling you to slow down when consuming cold food and beverages.

“Your body has quick reflexes that help to protect the brain from sudden changes in temperature,” he tells SBS Science.

Dr McKay explains that the blood vessels that travel up through the head to the brain – the internal carotid artery and the anterior cerebral artery – are responsible for maintaining a constant temperature and hence play a key role in how your body responds to the sudden cold stimulus.

“By having cold food or drink in your mouth, you can chill the blood as it flows up to your brain,” he says.

“Your arteries quickly constrict from the cold, and then your reflexes will cause them to rapidly expand to let through more warm blood.”

This rapid constriction and dilation of the blood vessels triggers stretch and pain receptors in the brain, which then sends pain signals down the trigeminal nerve that is responsible for sensation in the face and controlling muscles for biting, chewing and swallowing food.

As a result, you experience an intense sensation of pain across your forehead that can from just a few seconds to a few agonising minutes.

“The sudden pain causes us to stop scoffing down our ice-cream, prevents further cooling, and ultimately keeps our brain at a happy temperature”

“The sudden pain causes us to stop scoffing down our ice-cream, prevents further cooling, and ultimately keeps our brain at a happy temperature,” says Dr McKay.

Although you can have a brain freeze during any season of the year, you are more likely to experience on a hot day as the temperature change that triggers it is more extreme.

It turns out that people who suffer from migraines are also more likely to get a case of brain freeze – the mechanisms behind migraines are still not completely known, however research suggests this blood vessel-nerve connection in sphenopalatine ganglioneuralgia holds the key to understanding it.

Dr McKay says that the easiest way to avoid an ice-cream headache is to simply eat your ice-cream or drink your slurpee slowly, but for those who can’t resist the urge to scoff it down there is a simply remedy.

“Brain freezes are usually gone within seconds, but pressing your tongue to the roof of your mouth can make the headache go away even faster,” he says.

“Heat from your tongue helps raise the temperature of your palate and rapidly increases the temperature of your blood to normal levels.”

And we’re not the only ones who should heed this advice – cats, dogs and even otters can also experience brain freezes, but this could be occurring through other mechanisms such as nerves in the teeth.

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