The reasons for headache after drinking liquor are as follows: first, drinking liquor will cause sudden osmotic pressure increase in intracranial pressure, under the effect of the osmotic pressure of liquor, the increase in intracranial pressure will lead to sudden headache, accompanied by visual dizziness, rotation, blurring, optic papilledema, etc., which will not necessarily increase blood pressure at this time, but the increase in intracranial pressure will lead to severe headache. Second, based on the original cerebrovascular diseases, drinking liquor because of the high degree of alcohol in liquor will increase the cerebrovascular load, increase the cerebrovascular load will make the cerebral vascular permeability increased, which will lead to headaches, serious cases will also appear cerebral hemorrhage, cerebral thrombosis and cerebrovascular disease. Thirdly, excessive drinking of liquor will lead to increased release of inflammatory factors in the body, such as bradykinin, histamine, prostacyclin, etc. Such inflammatory mediators will lead to the release of inflammatory factors in the body that increase and sensitize the headache, which will also lead to headaches after drinking liquor.