HOW BRAIN FREEZE HAPPENS

Technically called sphenopalatire ganglioneuralgia, ice cream headaches are related to migraines

The pain of a brain freeze, also know as an ice cream headache, comes from your body’s natural reactions to cold. When you body senses cold, it wants to conserve heat. One of the steps it takes to accomplish this is constricting the blood vessels near your skin. With less blood flowing near your skin, less heat is carried away from your core, keeping you warn.

The same thing happens when something really cold hits the back of your mouth. The blood vessels in your palate constrict rapidly. When the cold goes away (because you swallowed the ice cream or cold beverage), they rapidly dilate back to their normal state.

This is harmless, bit a major facial nerve called the trigeminal lies close to your palate and this nerve interprets the constriction/dilation process as pain. The location of the trigeminal nerve can cause the pain to seem like its coming from your forehead. Doctors believe that this same misinterpretation of blood vessel constriction/dilation is the cause of the intense pain of a migraine headache.