How many of us have eagerly taken that first bite of ice cream on a hot day only to be met with searing head pain? “Brain freeze,” the phenomenon of sudden, severe headaches related to the rapid consumption of cold food or beverages is a common phenomenon that almost half of people experience. Some may know it as an “ice cream headache” or a “cold-induced headache” and neurologists refer to it by the elaborate name of “sphenopalatine ganglioneuralgia.”

The Cause
While the symptoms are severe, the effects of brain freeze are quickly reversible, and not a sign of disease. The actual underlying cause of brain freeze is unknown because the effects are short-lived and difficult to study, but there are several theories about why they may occur.

The most common theory is that the sudden stimulation by cold temperatures to the roof of the mouth or back of the throat results in a rapid constriction of the small blood vessels located in that area. In turn, this activates the pain receptors in the trigeminal nerve, the nerve that perceives pain and temperature sensations from the inside of the mouth. The trigeminal nerve relays this information to the brain cortex, where the signal of pain and cold temperatures emerges into your consciousness.

But why would shrinking blood vessels in your mouth cause a sharp pain in your forehead? Since the trigeminal nerve also supplies the sensation to the head and scalp, your brain interprets this as pain coming from the head. This mix-up in where your brain perceives the stimulus is called referred pain.

Studies have shown that brain freeze can occur more frequently in patients who have migraines. Age, associated symptoms and family history can all be factors.

How to Avoid It
Besides putting cold food and drink in your mouth, brain freeze can also occur with cold stimulation to the face and head. There have been reports in the medical literature that this can occur occasionally when a dermatologist freezes off skin lesions on the face and scalp, and there’s even a report of a surfer who had brain freeze when trying to surf in the winter weather!

Since brain freeze is thought to occur with a rapid change in temperature, there may be some strategies to help reduce the effects and prevent a headache from occurring. Some experts suggest touching your tongue to the roof of your mouth in between bites of cold foods like ice cream, which would help warm up your mouth in between each bite. Eating ice cream more slowly may also help, but what’s the fun in that?

Sarah M. Jones is a physician and an assistant professor in the UVA Department of Neurology.