Do you feel sharp and stabbing pain in your head just after you eat or drink something too cold? It is basically brain freeze. Also known as cold stimulus headaches, brief pain occurs when you indirectly expose your brain to cold temperature. The condition is characterized by peak pain for 20 to 60 seconds. Rarely, the pain lasts for more than five minutes. Though the exact mechanism behind this process is unknown, scientists believe that the sudden cold temperature changes the blood flow in the nervous system leading to a headache for an extremely short time. Actually, when you have something cold, the blood vessels constrict themselves to compensate for the lost body heat and then relax to resume the blood flow. This is what causes a sudden burst of pain. Watch this video to know what our expert has to say about this condition.Also Read - Why ice creams give you 'brain freeze' decoded Also Read - Brain Freeze: Now you can enjoy chilled beer slushies!