The Cause Of Freezer Head Revealed

Why does love (of ice cream) got to hurt so bad?

The researchers monitored the blood flow through their brains using an ultrasoundlike process on the skull. They saw that increased blood flow to the brain through a blood vessel called the anterior cerebral artery, which is located in the middle of the brain behind the eyes. This increase in flow and resulting increase in size in this artery brought on the pain associated with brain freeze. [Top 10 Mysteries of the Mind]

When the artery constricts, reining in the response to this increased flow, the pain disappears. The dilation, then quick constriction, of this blood vessel may be a type of self-defense for the brain, the researchers suggested.

"The brain is one of the relatively important organs in the body, and it needs to be working all the time," study researcher Jorge Serrador, of Harvard Medical School, said in a statement. "It's fairly sensitive to temperature, so vasodilation [the widening of the blood vessels] might be moving warm blood inside tissue to make sure the brain stays warm."

This influx of blood can't be cleared as quickly as it is coming in during the brain freeze, so it could raise the pressure inside the skull and induce pain that way. As the pressure and temperature in the brain rise, the blood vessel constricts, reducing pressure in the brain before it reaches dangerous levels.