A hangover is an indication of mild alcohol poisoning. There are three things you should do:
1. Eat or drink something salty, like chicken noodle soup. This will help to resupply the sodium content in your body and other electrolytes, this will help you rehydrate.
2. Eat or drink something sweet. Sugar will metabolize quickly and will aid your body in metabolizing any alcohol left in the body.
3. Drink a lot of water, you need hydration and you should drink as much water as possible, this will help your body expel any poisons in your body.
Do not take analgesics such as tylenol or ibuprofen, these are hard on the liver and kidneys. When your body is recovering from too much alcohol, the kidneys and liver are being overworked.