Physiological effects of brain freeze


photo courtesy of Royal Ball Photography

We’ve all been there.  Eat too much ice cream at once or too pound a slurpie as quickly as possible and then your head explodes.  That shooting pain drives right at the front of your forehead.

As often as this happens, I’ve never stopped to wonder what drives that headache, what the cause of it actually is.  Researchers suggest it is a combination of your body’s overreaction to cold stimuli, the freezing of a cluster of nerves above the hard palate and a sudden influx of warm blood to the brain.  The initial contact between the cold food and the roof of your mouth sets all of this brain freeze activity in motion.

To the best I can find, here are the physiological effects of brain freeze:

  • When cold things touch the roof of your mouth, they activate a particular nerve, or bunch of nerves, in the sphenopalatine ganglion (sometimes known as the pterygopalatine ganglion).
  • The sphenopalatine nerves are responsible for sensation and glandular work in your palate (roof of mouth).
  • If the roof of your mouth doesn’t have time to warm up and those nerves don’t have time to relax, the nerves will tell the blood vessels in your brain to contract and then swell with a rush of warm blood. The theory is that these nerves do this as a sort of misguided way of trying to keep your brain warm.
  • When blood vessels in your brain swell, you experience that as pressure, or a headache.
  • While all of these blood vessels are busy shrinking and reopening with warm blood, the nerves are also contributing to the pain of brain freeze. The pain receptors near the sphenopalatine nerve cluster sense the freezing of the palate, but the pain itself is referred to another area deeper in the skull. This is why you feel brain freeze deep inside your head and not in the roof of your mouth.
  • The headache will usually subside on its own within 10 to 20 seconds.
  • But if you want to make the headache go away faster, you have to warm the roof of your mouth. You can do this by pressing your tongue to the roof and waiting a bit, or by drinking warm water.
  • 7-11 owns the trademark to the word “brainfreeze.”

Sources: Kidzworld, The Chilling Truth About Brain Freeze; Howstuffworks, What causes an ice cream headache?; The Straight Dope, What causes “ice cream headache?” June 28, 1991; Biology Online, definition of sphenopalatine ganglion and definitions of related terms; Joseph Hulihan, Ice cream headache, British Medical Journal, May 10, 1997

Comments on this entry are closed.

  • Calgary Tutors May 19, 2011, 2:54 pm

    This is an interesting post and will share it with some of the students I tutor in biology. Thanks!