What causes brain freeze?

One minute you are enjoying your favorite ice cream, and the next minute, you have an excruciating headache that seems to come from the middle of your skull. This horrible experience is known as brain freeze. The pain is similar to that of a migraine headache, but most attacks of brain freeze only last about 30 seconds or less.

Scientists think brain freeze is caused by a combination of your body’s over reaction to the cold “freezing” of a bundle of nerves above the palate, and a sudden surge of warm blood to the brain. The initial contact of the ice cream and the roof of your mouth is what causes the brain freeze to begin.

When you took a big bite of ice cream, some of it touched the roof of your mouth. Behind the hard palate is a cluster of nerves that act as a protective thermostat for your brain. The main nerve in this bundle is extremely sensitive to abrupt changes in temperature. When the ice cream cools down the main nerve, the nerves send a warning signal to the other nerves in the bundle. The nerve bundle then “tells” your brain to get ready for a major freeze.

Your brain and the nerves don’t actually freeze during brain freeze. The nerves over reacted to the cold and confused the ice cream for hypothermia. The blood vessels surrounding the brain suddenly shrink in response to the cold to retain heat. The result is a pounding headache. The pain is not due to the vessels constricting, but by warm blood flooding back into the constricted vessels. A similar, but painless, blood vessel response is what makes you have red cheeks on a cold day.

While the blood vessels are busy shrinking and reopening with warm blood, the nerves are also contributing to the pain of brain freeze. The pain receptor near the nerve cluster sense the freezing of the palate, but the pain itself is moved to an area deeper in the brain. This is why you feel brain freeze deep inside your head and not in the roof of the mouth.

One way you can relieve the pain is to press your tongue against the roof of your mouth to warm the area up.