A headache that occurs the day after drinking alcohol is considered to be delayed-onset pain after drinking. Drunken headaches can be categorized into two types, which are classified as rapid onset pain and delayed onset pain after drinking. Fast-onset pain is pain that occurs within 3 hours of drinking alcohol and late-onset pain is pain that occurs within 5-12 hours of drinking alcohol. So a headache the day after drinking alcohol falls under the category of delayed-onset headache after drinking alcohol. The first thing you can do to relieve a headache the day after drinking is to get enough sleep, and some people can get significant relief from headaches after a full night’s rest. You can also drink more water, which helps the alcohol in the body to decompose and evaporate quickly, thus relieving the symptoms of headache after drinking. If the headache is caused by intoxication, it can usually be relieved within 72 hours. If it exceeds this time, it should be suspected that this is not a headache caused by drinking and the patient should go to a regular hospital. Delayed-onset headaches usually refer to hangover pain after drinking alcohol. Patients are advised to drink appropriately the day before; excessive alcohol consumption can cause pain.