What is a brain freeze?

A brain freeze, or the sudden, stabbing pain in the head caused by eating or drinking something cold, is actually a type of headache. The sensation is limited to the forehead and temple area, and resolves within 10 minutes after removal of the cold stimulus, according to the International Classification Of Headache Disorders (ICHD-3). 

The pain of brain freeze can begin within seconds of being exposed to cold temperatures, and the pain peaks quickly, often within seconds of onset. Some people may describe the discomfort as a stabbing or aching type of pain, while individuals who have migraines may perceive it as a throbbing or pulsating pain, Dr. Stephanie Goldberg, a neurologist and clinical development associate medical director at Vertex Pharmaceuticals in Boston, told Live Science. 

Why do you get brain freeze?

Despite brain freezes being so common, doctors are not quite sure why it happens, Goldberg said. The research on the causes of cold stimulus headaches is scarce. However, available evidence suggests that there is a link between brain freeze and changes in the blood flow in some of the brain's blood vessels.  

The brain itself cannot feel pain because it contains no nociceptors — the nerve fibers present in the skin, muscles, joints and some organs that transmit pain signals. The brain's lack of nociceptors is why surgeons can operate on the brain without directly applying anesthesia to the organ, although they still anesthetize the overlying scalp. The dura and pia, or protective membranes between the brain and skull, do contain nociceptors. Mechanical pressure or changes in blood flow can stimulate these membranes, which can lead to pain, according to a 2018 study published in the journal Brain.  

When a very cold substance hits the roof of the mouth or the back of the throat, it causes blood vessels inside the head to momentarily tighten and constrict and then rapidly dilate or widen. This in turn stimulates the trigeminal nerve, which is a group of highly sensitive nerve fibers located behind the nose. Once the trigeminal nerve is triggered, it relays the information to the entire head. That is why you feel a brain freeze in your head and not in your mouth or nose, where the cold sensation originated, Goldberg told Live Science.

When the cold stimulus is removed, the blood vessels go back to their normal size.  

A 2012 study published in The FASEB Journal found that the sudden increase in blood flow and resulting increase in size of the anterior cerebral artery, a blood vessel that snakes across the midline of the brain behind the eyes, may trigger brain freeze pain. The study found that when patients' brain freeze ended, the artery constricted and reduced blood flow, which is likely what caused the pain to disappear. That suggests an increase in pressure within the skull, brought on by increased blood flow to the head, is what causes the pain, the researchers wrote in the study. 

Is brain freeze ever dangerous?

Brain freeze does not cause permanent damage and is not life-threatening, Goldberg said. Nonetheless, several case reports reported a possible link between cold stimulus headaches and paroxysmal atrial fibrillation, a type of an irregular heartbeat that happens occasionally and usually stops on its own within seven days. However, this is not thought to be a common occurrence.

A 2022 case reported published in The Permanente Journal described a 63-year-old woman diagnosed with paroxysmal atrial flutter and atrial fibrillation, who claimed that consuming cold food and beverages triggered her recurrent episodes of heart palpitations. The patient had no prior diagnosis of coronary artery disease, heart failure or other arrhythmias. 

Similarly, a 2016 case study published in the American Journal of Case Reports described a healthy young man who drank a slushed ice beverage that immediately induced atrial fibrillation and a brain freeze headache simultaneously. This happened on two separate occasions, years apart. During both episodes, the acute brain freeze resolved itself quickly, but the palpitations prompted the patient to visit the emergency department for diagnosis and treatment.  

And in 2001, doctors in The American Journal of the Medical Sciences described a man and his father simultaneously developing atrial fibrillation immediately after eating a frozen sweet, despite neither having prior history of cardiovascular problems. 

The exact cause behind this association is unknown. The 2016 case study authors suggested that since the esophagus lies in close proximity to the vagus nerve — a long nerve that carries information between the brain and the internal organs — cold foods could potentially influence heart rhythms. Another theory is that atrial fibrillation could be triggered by gastroesophageal reflux disease or an excessive response from the autonomic, or involuntary, nervous system to the act of swallowing cold substances. 

Still, more research is needed to understand why this happens, and who may be at risk of developing such a reaction to brain freeze. Thankfully, it is not a common occurrence and only a few such cases of atrial fibrillation have ever been documented.

Who may be more susceptible to brain freeze? 

People who have migraines might be more prone to brain freeze than those who don't have the headache disorder. People who have migraines often have a sensitive trigeminal nerve and a cold stimulus can activate this nerve pathway even more, Goldberg said.

A 2003 study published in the journal Cephalalgia investigated the phenomenon of "ice cream headache" among 8,359 school adolescents in Taiwan using a self-administered questionnaire. Researchers found that the overall lifetime prevalence of brain freeze was 40.6%, while students with migraine had a higher frequency of ice-cream headache compared with the students without migraine (55.2% vs. 39.6%). 

A 2004 study in Cephalalgia looked at 76 migraine patients and 38 people who had episodic tension-type headaches. Researchers attempted to induce an "ice-cream headache" in participants by having them each hold an ice cube to the roof of their mouth, and they observed that cold stimulus pain in the head occurred in 74% of migraine patients and 32% of the other participants. Both groups most frequently reported pain in the temple, but migraine sufferers were more than twice as likely to report feeling pain at this particular location than the other group.

How do you prevent brain freeze?

The pain of brain freeze is so fleeting that there is no need to treat it, but it can be tricky to avoid, Goldberg said. However, certain strategies could help minimize the chances of developing a cold stimulus headache. 

One way to prevent brain freeze may be eating cold food and drinks more slowly, according to a 2002 study published in the journal BMJ. In this experiment, 145 middle school students were split into two groups, where one group was instructed to eat roughly a half-cup of  cream in more than 30 seconds, while the other group had to eat the same amount of ice cream in less than five seconds. 

The researchers — one of which was a middle schooler, herself — found that 20 of the 73 students in the fast-eating group experienced brain freeze, while only nine of the 72 students in the cautious-eating group did.

Another possible strategy could involve keeping the cold substances away from the upper palate, Goldberg said.

Johns Hopkins Medicine recommends promptly removing the cold food or drink from your mouth and pressing your tongue or (clean) thumb to the roof of your mouth, to warm it up. Drinking warm water can also help.