What causes brain freeze?

Brain freeze, that instant headache you can get when eating cold ice cream, involves the nerves and blood vessels in your face, mouth and brain.

The scientific name for this phenomenon is sphenopalatine ganglioneuralgia, and the mechanics behind it may also have something to do with migraine headaches.

Here's what may be happening. When you eat something very cold, nerves in the roof of your mouth sense the extreme cold, causing blood vessels to constrict. The body reacts by instantly sending extra blood flow to the area to protect it from the cold. The extra blood flow increases the pressure in the brain and gives you a headache. 

That's just one theory. The pain you feel isn't necessarily in your brain. It may be referred pain from the lining of your brain or from your face. Referred pain is very common—the network of nerves in your body leading to your brain is so complicated that sometimes the pain from one area gets transferred to another area. It's like when people feel shoulder pain when they are having a heart attack. 

The best way to stop brain freeze is to sip warm water or hold your tongue to the roof of your mouth to warm it up. Or, just savor that ice cream by taking smaller bites and eating it more slowly.