The symptoms of headache can occur after drinking alcohol, mainly for the following reasons: First, caused by allergy to alcohol, if you are usually allergic to alcohol, you will have an allergic reaction after drinking alcohol, the common symptoms are headache, nausea, red face, hives and so on. Second, alcohol into the body can stimulate the blood vessels in the brain to cause cerebral artery spasm or dilation, cerebral artery blood supply is insufficient to cause headache, dizziness and other uncomfortable symptoms, drinking alcohol can cause a certain disease appear headache, the most common disease is migraine. If you usually have migraine symptoms, drinking alcohol may trigger an acute attack of migraine and cause headache and nausea, etc. It is recommended to stop drinking, eat a light diet, exercise properly and monitor blood pressure regularly.