I HAVE experienced a painful headache after eating ice cream too fast. Called as brain freeze, or the sudden, stabbing pain in the head caused by eating or drinking something cold, it is actually a type of headache. The sensation is limited to the forehead and temple area, and disappears within 10 minutes after removal of the cold stimulus.

The pain of brain freeze can begin within seconds of being exposed to cold temperatures, and the pain peaks quickly. 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  pain.

Despite brain freezes being so common, doctors are not sure why it happens. The research on the causes of cold stimulus headaches is scant. But 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.

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.

When the cold stimulus is removed, the blood vessels go back to their normal size. Brain freeze does not cause permanent damage and is not life-threatening. But people who have migraines might be more prone to brain freeze than those who don’t have the headache disorder.

The pain of brain freeze is so transitory that there is no need to treat it, but it can be tricky to avoid. But 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. Another possible strategy could involve keeping the cold substances away from the upper palate. It is recommend to promptly remove 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. By Manny Palomar, PhD (EV Mail July 31-August 6, 2023 issue)