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- Brain freeze is a splitting headache that happens when you eat or drink something cold too fast.
- When you consume a cold food or beverage, you cool down the blood flowing to your brain.
- The headache that you feel is an alarm designed to tell you that the blood is too cold.
- Visit Insider's Health Reference library for more advice.
Eating or drinking something cold too fast can trigger a splitting, short-lived headache. This sudden phenomenon, technically called sphenopalatine ganglioneuralgia, is more commonly known as brain freeze or an ice cream headache.
It can be extremely uncomfortable, but luckily, it's harmless. Here's the science behind brain freeze and why it happens.
What causes brain freeze?
Consuming cold foods or beverages cools down the roof of your mouth and throat. Right behind those areas is a major artery that delivers blood to the brain, called the internal carotid artery. This means that eating cold things actually cools down the blood that's flowing to and from your brain, says Greg McLauchlin, MD, Assistant Professor of Neurology at Baylor College of Medicine.
When the blood flowing to your brain gets too cold, your brain sets off an alarm – causing the headache known as brain freeze. This alarm warns you to stop or slow down the consumption of cold foods or beverages so that the temperature of the brain remains regulated.
This is why a brain freeze headache can hurt so badly: "Your brain has to send a signal that you cannot ignore. It can't be a tickle. It can't be an itch. It has to be something that makes you stop," says McLauchlin.
In fact, brain freeze actually activates the trigeminal nerve, which is responsible for extreme pain. And if you've had that sudden, acute brain freeze sensation, you know that the pain is impossible to ignore.
If you didn't stop, "the blood vessels containing the cold blood can be constricted so that they do not make up as much of the circulation. As a last resort, you pass out and drop the ice cream cone. Don't let it come to that," says McLauchlin. Though, the chances of this worst-case-scenario happening are very unlikely.
How long brain freeze lasts and how to treat it
Unlike migraines and other types of headaches, brain freeze pain will usually dissipate in 30 seconds or less, says McLauchlin. But it can last up to a couple of minutes.
The way to "treat" brain freeze is to stop or slow down the consumption of whatever is triggering the pain.
"It only lasts as long as it takes for the blood to warm back up. And so the faster the blood warms up, the shorter it lasts," says McLauchlin.
If you want it to go away even quicker, you can have a warm drink if you have one handy.
Once the brain freeze dissipates, you can get back to enjoying your food or beverage - more slowly this time.
Insider's takeaway
When you drink a cold beverage, you cool down the blood flowing through the internal carotid artery, which runs right behind the mouth and throat and to your brain.
Your body alerts you that the blood flowing to your brain is too cold - resulting in the painful sensation of brain freeze. To get relief, try drinking a warm beverage.