Why do you get brain freeze?
When you eat or drink something very cold, the roof of your mouth and the back of your throat get very cold very quickly. This causes the blood vessels in these areas to constrict. When the blood vessels constrict, they become narrower, which reduces the amount of blood that can flow through them. This can cause a headache or brain freeze.
Brain freeze is usually a harmless condition that goes away on its own after a few minutes. However, if you experience brain freeze frequently, you may want to talk to your doctor.