Now that summer’s heating up, we’re all prone to one of the shortest-lived pain conditions: a brain freeze. If you’ve gotten a headache while eating something cold too fast and imagined ice crystals forming on your brain, well you’re not exactly right. That’s not what causes a brain freeze. Here’s what does cause this phenomenon.

What causes a brain freeze?

Rather than ice crystals forming, sudden coldness sends your facial capillaries and nerves into a kind of panic. These lead to an “ice cream headache.” While heat expands blood vessels and improves circulation, cold has the opposite effect. It constricts your blood vessels. This makes it more difficult for blood to properly circulate.

When you eat or drink something very frigid, such as ice cream, a popsicle, or an icy beverage, the chilled substance comes in contact with the roof of your mouth (also known as your palate) and throat area. Many small blood vessels run from these areas to other parts of your head.

The ice cream or other cold food quickly constricts the blood vessels in your palate. This is true even though your blood is being continuously warmed by your body’s circulation patterns. The effect is a rapid constricting and swelling (cooling and warming) of tiny blood vessels above your mouth and in your sinuses. Nearby pain receptors sense this. These pain receptors then send signals to your brain via the trigeminal nerve.

This is also one of the most important nerves for recognizing and transmitting facial pain. When the signals from your palate and sinuses reach your brain, the brain interprets them as facial pain, also called “referred pain.” And, this is actually what causes a brain freeze.

trigeminal nerve

What does a brain freeze feel like?

Typically an ice cream headache will feel more prevalent on the same side of your head that the food or drink came in contact with on your palate. For some, though, the headache will feel as though it’s on both sides of your head after you swallow.

This competing constriction and swelling of capillaries is coincidentally very similar to your body’s response when you come inside from being out in the cold. While outside in the low temperatures, your skin and the tiny blood vessels around your cheeks and nose are cold and constricted. When you come inside they warm up again, dilating and causing you to appear flushed.

A brain freeze can happen any time of year, no matter the temperature outside. The reaction is dependent upon the temperature of the substance touching the roof of your mouth. It’s not affected by the temperature of your surroundings.

How long does a brain freeze last? 

The good news is: Whenever it may strike, an ice cream headache is short-lived. Usually it comes on within ten seconds and lasts only about 20 seconds. However, some people can experience the effects for up to a few minutes.

As researchers from Wake Forest Baptist Medical Center explain:

“Brain freeze is really a type of headache that is rapid in onset, but rapidly resolved as well. Our mouths are highly vascularized, including the tongue — that’s why we take our temperatures there. But drinking a cold beverage fast doesn’t give the mouth time to absorb the cold very well.”

To prevent a brain freeze, it’s best to enjoy cold foods and drinks slowly. To stop one, you can also press your tongue to the roof of your mouth or drink a warmer liquid to balance out the temperature.

If you’re suffering from severe head pain beyond a summer-time freeze, it may be time to talk to a pain specialist. You can find a pain doctor in your area by clicking the button below or looking for one in your area by using the tips here:

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