Ice Cream Headaches Explained

If you’ve gotten a headache while eating something cold too fast and imagined ice crystals forming on your brain, that’s not what causes a brain freeze. In reality, the coldness is sending your facial capillaries and nerves into a kind of panic.

While heat expands blood vessels and improves circulation, cold has the opposite effect — it constricts blood vessels and 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, from which many small blood vessels run to other parts of your head.

The ice cream or other cold food quickly constricts the blood vessels in your palate, although 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 that is sensed by nearby pain receptors.

These pain receptors then send signals to your brain via the trigeminal nerve, one of the most important nerves for also 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.” This is actually what causes a brain freeze.

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, or the headache could 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 after having just 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 were 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, because the reaction is dependent upon the temperature of the substance touching the roof of your mouth, not the temperature of your surroundings.

The good news is: Whenever it may strike, an ice cream headache is short-lived, usually coming on within 10 seconds and lasting only about 20 seconds, although some people can experience the effects for up to a few minutes. To prevent one from occurring, it’s best to enjoy cold foods and drinks slowly.

Image via Kathy Mackey on Flickr