Some alcohol is drunk with headache because after alcohol is absorbed from the esophagus to the stomach, it is rapidly transferred to the liver, where it is broken down into ethanol by the action of ethanol dehydrogenase, and ethanol is converted into acetaldehyde by the action of acetaldehyde dehydrogenase in the liver. Acetaldehyde is a very harmful substance that will cause dramatic capillary dilation and increased microcirculatory permeability, especially in the head microcirculation, thus producing severe head pain. Therefore, if there is too much acetaldehyde in the body or too much acetaldehyde in alcohol, it will produce severe headache, especially high alcohol, which contains more ethanol, will decompose a lot of acetaldehyde. Non-pure grain brewed wine, which has a high concentration of alcohol, will also be rapidly converted into acetaldehyde, resulting in head pain.