Mind & Body

Why Do You Get Brain Freeze While Eating Icy Treats?

One second you're gulping down the most delicious milkshake you've ever had, and the next, your head is throbbing in horrendous pain. All good things must come to an end, they say, but why does it have to be such a terrible one? The mind-aching side effect of indulging just a little too much in your favorite icy treat actually has a scientific name: Sphenopalatine ganglion neuralgia.

Related: Why Do We Get Brain Freeze?

Ice Pain in the Membrane

While "sphenopalatine ganglion neuralgia" probably means nothing to you, it means a lot to doctors and researchers that have spent time trying to understand why brain freezes happen. When you place something ice-cold in your mouth and let it come in contact with your soft palate, it touches a small bundle of nerves near the back of your mouth. This group of nerves we can all thank for the brain freeze effect is called the sphenopalatine ganglion, or SPG. It's sensitive to changes in temperature and when it's stimulated by an icy treat, it causes a headache.

The stark and painful reaction to cold is actually a biological reaction to keep your brain at the right temperature. When you drink or eat something too cold, it rapidly cools the area at the back of your throat, which is home to the junction of two important blood vessels: the internal carotid artery that feeds blood to your brain, and the anterior cerebral artery, which is where brain tissue starts. It's also where you'll find the SPG. The temperature shock causes these arteries to rapidly dilate and contract, which triggers the SPG and sends a message to your brain through the trigeminal nerve to let it know that you're experiencing pain.

The pain of brain freeze isn't in your brain, as the brain doesn't have any pain-sensing fibers. However, receptors in the outer covering of the brain, called the meninges, do. That's why brain freeze will often occur somewhere completely separate from your mouth: This nerve signal travels all the way to the meninges on the top of your head, causing a painful headache.

All this seemingly misplaced pain is just your head trying to figure out what's going on. Biologically speaking, this pain response is similar to what people going through a heart attack feel. During a heart attack, you don't feel like your heart is hurting; rather, it's your shoulder and your left side that hurt. This transferred pain is a result of your brain doing its best to interpret and communicate what's wrong using the pain sensors it has.

In the case of brain freeze, this headache reaction is useful: It keeps us from eating more ice cream, thus keeping the brain's temperature at a healthy state. The brain usually likes to stay in a resting range of 98.6 to 100.4 degrees Fahrenheit (37 to 38 degrees Celsius), but it can get much colder without damage under supervision. Surgeons will often chill the brain to 68 degrees Fahrenheit (20 degrees Celsius) to correct circulation and other brain issues with no lasting damage, but all under sedation. Ultimately, the SPG is in place to help protect the brain from slipping out of its optimal state, but it can handle the shock for a little while. If you can deal with the skull-aching pain of a brain freeze, you can keep slurping if you'd like.

Put a Freeze on Brain Freeze

Now that you understand a little more about the functionality and cause of brain freeze, how do you stop it? The best method for treating brain freeze once you have it is to press your tongue or thumb on the roof of your mouth. The heat of your tongue or thumb rapidly warms the SPG, which then tells the brain to stop the pain response. You can also cover your mouth and nose and breathe into your hands to circulate warm air, which can also raise the temperature of your soft palate.

You can also try and prevent brain freeze in the first place. Try eating the cold food near the front of your mouth, away from the SPG, or just enjoy it more slowly to give your palate time to adjust. Who's ready for a milkshake?

Get stories like this one in your inbox each morning. Sign up for our daily email here.

For more scientific answers to everyday questions, check out "Ask a Science Teacher: 250 Answers to Questions You've Always Had About How Everyday Stuff Really Works" by Larry Scheckel. We handpick reading recommendations we think you may like. If you choose to make a purchase, Curiosity will get a share of the sale.

Written by Trevor English August 27, 2018

Curiosity uses cookies to improve site performance, for analytics and for advertising. By continuing to use our site, you accept our use of cookies, our Privacy Policy and Terms of Use.